Sleeping under the stars in northern Mn when the temps were deep in the minus zone was a nice experience, but I always had a warm cabin nearby once I woke up. Still do that on occasion and have pondered setting up a winter gathering of canoeist at the cabin. Spent a few weeks there after Christmas and a few hardy paddlers snowshoed in the 3 mile long winter access trail to talk canoeing and stayed the night. Clear and -27 that night but everyone slept inside content with the crackling fire in the woodstove instead of the pops of freezing trees under the stars.