These are a few things I thought of just off the top of my head. They may or may not work, depending on your circumstances. Use them as you see fit.
- Sleeping bad - it will work better than blankets
- shovel - if you're in a cold weather area, it's useful for clearing snow. There are collapsible models where the handle is made of sections of metal tube that stow in a small package. Find out where your exhaust pipe is located, and be sure to clear that of snow if you get stuck in a snowbank.
- jumper cables - and learn how to use them, and practice the skill
- cell phone - although just about everyone has one now. Find numbers for towing services along the way, and put them in the phone now. It will be much harder to do so when you're stuck.
- cell phone car charger
- winter boots - if you tend to wear girly shoes, you won't go far in open toed shoes in snow.
- a gift card or two for gas stations in your area. If you're caught in bad weather, running out would not be a good thing. Add this to your christmas wish list.
- something to eat. Granola bars are good, as they won't be harmed by cold, won't spoil, and don't have to be warmed to eat them.
I would NOT recommend you carry extra gas. This can turn into a catastrophic fire if it spills. You'd be better off to just be sure you never get below a third of a tank if the forecast calls for bad weather.
Also - a membership from AAA might be a good idea. Put it on your Christmas wish list, too. Just be aware that if/when you really need them in bad weather, the likelihood is that 500 other people will also, and you may end up waiting for them to arrive.
