I lived up in the mountains for many years, there are risks of frostbite, hypothermia, and death at some temps and no amount of wool will save you. You need heat, most of that time I had a fire place, when I was in a tenant situation the heat was maintained by the management company and we only paid electric, and it was natural gas heaters.

I’m wearing two sweaters even though it’s only 10C (50F) here. I’ve never lived somewhere where it gets very cold, so this is very cold to me.

Two T-shirts, think thin layers