And yeah, winter camping is cold. Fill up a nalgene with boiling water and throw it in your sleeping bag. Much lighter than a four season tent.
dludi:
A thermos with an insulator works better than a Nalgene bottle but, of course, the thermos is heavier. I couldn't find an insulator big enough to take a thermos, so I built my own using foam rubber and duct tape. At night, I first temper the thermos and then fill it with boiling water and put it inside the insulator and then inside my backpack. In the morning I have hot water for instant cocoa and oatmeal without getting out of my bag.
I suppose that you use your Nalgene bottle in the bottom of your sleeping bag to keep your toes warm. I don't put mine inside my sleeping bag. Too worried about it maybe leaking.
KC
