....you will be working in 2 of the coldest regions in the populated Americas (The Dakotas). Other than a building insulated to R40+, only specialized Arctic research vehicles and specialized military vehicles with "living units" can withstand -50F to -60F prolonged (often present in the Dakotas and Minnesota); imagine an old non-frost-free freezer with 4 inches of ice crystals inside it: the inside of an R10 to R18 camper will look that way or worse after a few nights sleeping inside it at -40F, -50F, -60F. Alaska is Florida-like compared to The Dakotas **interior continental winters** (just check last year's Alaska winter cold stats: they are Florida-like compared to Dakotas/Minnesota).
There is NOTHING in the realm of off-the-shelf RV units available to you at a **reasonable price** that will protect both your fuel system, water storage system, batteries and interior against those kinds of prolonged temperatures. You'll have to go to a specialized Arctic vehicle up-fitter for your needs. Or, pray that your schedule doesn't situate you in the Dakotas during the depths of winter.
Good luck to you,
S-
