Spam and tack. Tack lasts forever if stored right. Spam jelly and tack is bearable, and is full of complex carbs. Makes for a rough night.

Cans. I don't know about the freezing temps, but I have a few cans of beans in my truck that have been through freezing temps just fine. I like pop top varieties, mostly because I use the pull tab as a handle. Combined with a camp stove/good fire kit you would be picking in tall cotton.

Do not forget COFFEE!