I have two approaches to cold-weather foods. When I head out on a day hike in the snow-capped mountains, I always bring some Scottish shortbread (check the cookie aisle in the grocery store) and a thermos filled with about 4 cups of hot cocoa and a stick of butter. I’m sure this won’t make the American Heart Association’s top-ten food list, but in a winter setting, think mucho calories and fat. Your body's like a wood stove: you need to be tossing in some decent fuel if you’re going to contend with cold temps.
I once kept a journal of my food intake on a weeklong survival course in the subarctic and found that I averaged about 9,000 calories a day. No love handles at the end: the chow went in and much-needed BTUs came out.
When I am on overnight treks, I have one-pot meals of pasta, cheese, butter, chicken, and dehydrated veggies. Because my job keeps me on the road so much, my truck emergency kit has a 64-ounce cooking pot, eight instant soup packets, three freeze-dried dinners (like those made by Mountain Home), some shortbread, and a big jar of peanut butter. At the very least, carry some PB with you for back-up food should you get stranded in a blizzard—there's nothing like a few spoonfuls of peanut butter to get your metabolism going before changing a tire in 40 mile per hour winds.
If you want some excellent ready-made survival food, then purchase a package of SOS Rations. One package contains 3600 calories, comes in a bar that resembles shortbread, and is actually very tasty.