>>137236830F aint bad.
Ive stayed 4 nights in -9.4C before in a coleman 4 person tent.
Use a tarp under your tent, and use a properly rated sleeping bag with an insulating layer (sleeping pad) underneath it.
Dont set up where its windy either, or tie a tarp up as a windbreak outside your tent.
Also, I like to take a couple swigs of whiskey before i drift off. Warms me right up and I sleep like a log.
