The Mayan calendar is cyclic, and doesn't end dec21 that is a myth, it is simply the beginning of a new cycle. I wish people would stop claiming the Mayans predicted the end of days when it was BS pop culture that did!!!
I carry a minimal kit in the car, one of those safety/warm blankets, matches w/paper, couple of powerbars and basic first aid kit.
Definitely no water until spring depending on where you live(unless you just put it in at the beginning of a trip), you'd be better off melting snow than trying to melt a solid block of ice!