@GBWhite
Firstly, thank you for taking the time to respond to this thread. I appreciate your thorough and thoughtful response.
I need to be honest and say as much as I thought I knew about snakes and believed I was ready and understood snake keeping - I knew nothing

I know some may read this and find it frustrating or sad that someone would "just get a pet without doing their proper research first- how sad for the pet" etc etc but at least I am trying to learn now and I have gained immense knowledge through the people on this forum trying to help me out.
To get to your response I'll answer each point you've made-
Your question regarding where the heat mat is? It's under the enclosure. I have the thermostat prove inside the enclosure on top of his substrate.
1. Checking the temperature using a heat gun (or thermometer) and if necessary adjusting the setting on the thermostat so the temp under the hide reaches a consistent 32 - 34 deg C. ------
I have a heat gun that I use to check the temperature every so often under the hot hide. I also have a thermometer placed consistently inside the hot hide to keep an eye on the temps. My thermostat is set to 32 with a 2 degree divergence which means that the temps do go up to 34 never higher and then down to 30 degrees never lower. All of these things I learnt how to do on this forum after my very first post here and Sdaji asking me questions regarding what my temps were. Hopefully this all sounds correct.
2. Ensuring that the overall ambient temp is warm enough for the snake to maintain it's desired temperature whereby it starts to move about then enclosure actively looking for food. This can be achieved by covering the enclosure with a towel or better yet attaching cardboard or similar to the outside of the back and 2 sides of the enclosure using bluetack or a similar product. Also, if the lid is of mesh then placing a cover over half of the top on the warm hide side will assist in maintaining the heat even further. This way the cardboard and cover can be removed during the warmer weather.--------
With regards to ambient temperatures I have just allowed the temps to be the "room temp" so on some days through winter that could have been temps of 17 or at times maybe even lower. Each time I used the temp gun on the cold side I never read lower than 18 but mostly sat at 19/ 20 over that really cold period. The hot hide always remained consistent. Fluctuating between 30 and 34 degrees. The towel is a good idea and recently learnt that one from herpetology. I must admit recently I took it off because I was worried he would overheat ( even though I had left a portion uncovered) I will look into the cardboard thank you.
3. Consider replacing the substrate with something that will not impede any transfer of heat. Snakes don't care about aesthetics (we include them for our own benefit) and although it might not look as nice, sometimes paper towel or similar is more beneficial to the welfare of the snake.--------
I (think??) I shouldn't have issue with heat transfer due to how I have the heatmat and thermostat probe placed? But perhaps the Aspen is stopping some heat getting through? So that is food for thought on changing to paper towel thank you. Added benefit- no ingestion of Aspen when eating I guess
4. Move the enclosure to a low traffic area of the house and disturb the snake as little as possible.--------
We have him in a second living area that isn't used too often and usually reasonably dark so I'm really hoping that's enough. I will admit I'm guilty of disturbance more than I would like to admit but only due to my anxiousness in making sure he is okay. I have dialled that down now to once a week when I try and feed him. I will try and leave him alone for a full two weeks. Except if changing water of course which I do every few days.
5.Once the snake starts moving about it's enclosure and displaying signs that it is searching for food offer it a fuzzy mouse the same size as you have been (don't go back to offering pinkies as there is no benefit to doing this). You can offer the fuzzy two ways. Either by tempting it using a long pair of tweezers whereby holding the fuzzy with the tweezers around the mid body and lowering it to a level where it is on par with the snake and then, holding it in front of the snake, gently and slowly move it to attract the snake's attention with the aim to encourage it to strike and take the meal. Alternatively, if you've had previous success placing a fuzzy in the enclosure to allow the snake to find it of its own accord, then do that. Either way if and when it takes it leave it be to eat the meal. -----------
Ok upon reflection I probably hold it above his head so it probably looks very threatening coming at him like that? I will try getting the mouse more on par with his head thank you.
6. You can leave the fuzzy in the enclosure for a couple of hours or even overnight and If it doesn't take it then remove it and give it a week or even 2 and try again.---------
Another nice forum member recommended this to me which I tried but unfortunately didn't work, that's not to say it may not work in the future.
Its been said a few times about glass enclosures being no good but I do feel that I need to rethink my setup

but really wish I didn't have to. I like the glass.....
I'll attach some more reason pics of my little guy for you to assess and once again I appreciate your thoughtful response and understanding my worry. So very appreciated.
No worries, you're obviously very stressed and text can be very bad at delivering tone. No harm done there.
When it comes to anything related to animals/biology, there are very few absolutes. Diversity is actively conserved by evolution, it is one of the most important aspects to a population since if all individuals were the same, if a set of conditions occurred one year which would kill most or in some cases even all of that specific type of individual (such as if all individuals wanted to feed during winter and there was a sudden unseasonal cold snap, or if they all wanted to eat lizards and not birds or vice versa, they would all go hungry despite an abundance of feed, etc etc etc).
Your snake seems to be one which wants to play it safe during winter rather than take the risk and feed on the hope that conditions won't get too cold (they don't know that they're safe in a box, they instinctively think they are at the mercy of unpredictable weather).
There are plenty of tricks you can use, and some may be worth trying, but don't fall into the trap of harassing your snake. At absolute most, try feeding once per week. I'd probably go for every 2-3 weeks. Don't interact with the snake unless necessary. I encourage you to take a picture and post it here so we can confirm it is in good health - if it is losing condition (which I greatly doubt is the case, but is possible) you do want to get a feed into it ASAP, and in that case it's very important to give a feed of the correct size as a large feed can kill a particularly underweight snake. Once again though, from what you've said I'd be surprised if you're in that scenario.
Thanks so much Sdaji for your response. Makes complete sense what you said. Could you please look at the photos I've attached in my response to George and tell me what you think? These were taken last week I think.
Thanks heaps