Since you already own the truck, I'd look for the biggest hardshell camper you can find with all the amenities (shower/toilet, fridge/freezer, sink, heater, etc.). And find a friend with some land who will let you park and plug in (or run a generator) for a few hundred bucks a month. Not quite as nice as van living, but the advantages of the truck and 4WD are needed in a winter environment.