I camped about 20 miles from my home in a Fire safe area in the Forest at 8200' elevation last Saturday.
I finished up putting a 60w panel on my slide in pop up camper on Friday so I thought I would try it out.
I didn't have a thermometer, but it was cold enough that night to freeze a bottle of water I left on my ATV trailer.
I also installed a programmable thermostat so I set it for 50 degrees sleep time and to come on at 6:30 am and 70 degrees.
I'm an old guy and forgot about getting up in the middle of the night.
That was cold.
I was nice to be able to get up in a warm camper at 6:30.
I've camped in the same area in my Scamp
in a blizzard and was quit comfortable.
The town I live in is surrounded by the Sequoia National Forest and it's about 30 miles from here to the Mojave Desert so I do quit a bit of winter camping.
I was camped in some tall trees so my panel only had filtered light
was topped of when I came back for lunch at about 1 pm.