I've been deer hunting in those conditions. When you only have a 9 day season, you have to make the most of it. At night, the trees were freezing and popping apart - it sounded like rifle shots all night long. At night it was in the -30�F range.
The cabin that we were staying in was raised up off the ground by 2 cinderblocks. It had an oil fired furnace, one common room and 2 bedrooms. When we'd wake up in the morning, the water that melted off of our boots on the floor was froze. I remember Dad putting his felt boot liners on top of the furnace and we went to the main lodge to eat (his cousin owned the lodge and we ate with them). When we got back to the cabin, it smelled bad. He forgot to take the liners off of the furnace and he burnt holes in the bottom of them. We'd sleep inside out sleeping bags, under the covers on the bed. That was a very cold hunt!