We have lots of forest and no people. A couple dozen spruce or fir branches have no ecological cost.
When you're done, make a pile of them. Under deep snow, that becomes small animal habitat.
We have a third choice, called a "thermal" blanket. Looks quite ordinary, synthetic, but a very coarse weave.
One, maybe double thickness, is very warm.
I have 2 synthetic fleece blankets on my bed ( I sleep cold). Two thermal blankets would be warmer.
When you're done, make a pile of them. Under deep snow, that becomes small animal habitat.
We have a third choice, called a "thermal" blanket. Looks quite ordinary, synthetic, but a very coarse weave.
One, maybe double thickness, is very warm.
I have 2 synthetic fleece blankets on my bed ( I sleep cold). Two thermal blankets would be warmer.