Re: Sub-zero tent?
There are some simple one pole and or pole less canvas tents made Panther Primitives and Rk lodges and others. My 8 x 8 baker style takes poles to set up, but weighs only about 10 lbs without stakes etc. Small "A" frame tents can weigh less. A wood stove can mean stove pipe etc. A small alcohol or other stove can be less weight and more efficient.
An acquaintance used a small alcohol stove to heat his tent. It was basically a small dry gas can with a small wick sticking through a hole in the cap. He carried a spare cap to seal it. Alcohol burns very hot and nearly flameless. I thought it quite dangerous, but the heat that thing put out necessitated opening the flaps to cool off. He winter camped in an 8 x 8 wall tent.
Just a candle lamp can raise a wall tent internal temp by ten degrees.
There are several Youtube videos on snow caves and heating them. Depending on the snow cover, a snow cave is better than a tent. There is one such video that shows a small wood fire in a snow cave and how to build a firespot/chimney off to the side.
My winter rig requires a truck to haul it, complete with a 90 pound cast iron Jotul airtight wood stove.