Winter Box for Van Fridge

Hello everyone, I am posting here today because I have a small problem on my hands that I need to start engineering a solution for. I’ve been gradually converting a honda odyssey into a campervan over the past year, it’s coming along quite nicely, and the next step is to install a fridge. I’m looking at getting a Dometic dual zone chest fridge - one side will be refrigerated and the other frozen - and I’d like to be able to leave it in my van year round without turning it off… Which is an issue because that would necessitate leaving it in during the winter months, which is problematic because A) when the temperature gets below 40 degrees the fridge’s onboard thermostat gets confused between the temperature inside the fridge and the outside ambiant temperature and as a result the fridge stops functioning properly, and B) The fridge has no mechanism for heating items, so if the ambient temperature is below freezing, items that I ONLY want refrigerated will eventually freeze. I need to come up with some solution to keep the ambient temperature around the cooler at 45 degrees or higher during the winter. I don’t want to go through the trouble of heating the entire interior my van 24/7 all winter, that sounds like an outrageously expensive engineering nightmare, and that’s if its even feasible. My idea is to develop an insulated box/shell to house the fridge along with a heating pad; specifically a heating pad that utilizes a thermostat and activates when a certain pre-programmable temperature threshold is reached. The heating pad would keep the temperature inside the box at 45 degrees, thus solving my problems and making life easy!

I’d like to ask for some direction here: Has anyone here ever faced this issue before? What products would you recommend (especially in regard to a heating pad setup)? Are there any considerations I should take into account when designing this thing that one might easily overlook? Is there some place I could potentially go to commission someone to design this contraption for me? Any direction would be greatly appreciated. Thanks!