I had a wild idea to one day run a countertop across the dinette and build cabinets underneath, with space in the middle for a bigger fridge. It think it would work, but not without difficulty and you'd have to put a ton of thought into it to make it look good.
But a much more practical solution is to get a separate fridge/freezer for your truck. We have a National Luna 60 liter with separate fridge and freezer compartments and between that and the trailer fridge, we can keep three weeks of food safely. The fridge fits well in the cab of our F150 - I installed a mounting plate to keep it secure, which is hard to notice with the seat down. Installing the fridge is just flipping up the seat and sliding in the fridge. Access is easy. If you're full timing it, then I'd recommend one of their larger double door models, and I'd recommend getting a topper for your truck and installing it in the back.
You'll need a house battery for the truck, of course, and preferably solar to help recharge. I have a 200w panel I can attach to a rack over the bed and that does a good job except in the summer when it needs some drive time to keep up. Of course, if you have a generator for the trailer, you can use that on the house battery as well.