Winter bug-outs suck ass. I don't recommend it. Zombie's should be frozen, so you can probably just stay put until spring. If you need to get out of dodge over Christmas, than there are a few key things you should have in your kit.
Snowshoes, because trudging through knee-high snow in boots will burn you out.
Chapstick, because dry, wind-burnt lips will drive you nuts.
Thermos, because regular water containers will freeze. Anything non-insulated should be carried against your body. Your body heat will keep the water from freezing over.
Other than that, just be mindful of how you dress. If you step-off all bundled up for the cold, you will be sweating balls in an hour of hiking. Then you will stop, your sweat will freeze, and you will chill your body. Instead, dress so you are cold when you are standing still. When you start moving, you will be comfortable. When you stop for a break, and begin to cool off, it means its time to get moving again. Once you get to camp for the night, you can permit yourself to bundle up like a school child.
Soldier, out.
