My dark sky site is in the high desert at an elevation of about 3700 feet. In the winter it gets pretty, sometimes into the 20s but mostly it's just above freezing. But it's windy a calm night is under 10mph, a normal night is 10-20mph and some nights it's more. Last winter there was a night when my little weather station said it was 33F and the wind speed was 20-30mph the entire night.
I lasted 2 hours before calling it quits..
My typical winter clothing starts with thermal underwear, on top that I wear sweat pants and my jeans. For extra protection I have a couple of pairs of snowboarding pants. On my upper body, it's the thermal underwear, a heavy sweatshirt, a flannel shirt and a heavy jacket I bought while visiting my sister in law in Maine. For extra protection I wear a down parka under the heavy jacket. For me head I wear a fur trappers hat. For me feet, I wear thermal socks insulated boots.
The wind is what gets to me. And as I get older, it seems I am more sensitive to the temperature. 10 years ago, even 5 years ago, I didn't need to be so bundled up. But I am nearly 70, I just don't have the resistance to the cold I once had.