Why not use a tent, cot, good sleeping bag, and maybe a Mr. Heater?
If I were as far north as you I'd winter camp with a good brand -20 degree bag......such as Marmot, Western Mountaineering, ar Feathered friends all who make very good bags.
My wife and I use Marmot Couloir 800 fill zero degree bags and only turn on the heater just before we go to bed, and just before we get up. A good cot gets you up off the ground and helps you get you a good nights sleep.
For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.