That's why I don't winter camp. The nights are just too long! Up here it's dark 15 hours a day in December and January. I also got turned off winter sports after I ripped nearly all the ligaments in one knee x-c skiing 20-some years ago. I dayhike at lower elevations, but no camping for me from mid-October to early March. I can take 12 hours in the tent, but no more.