Semi Off-Topic: In snow/ice/rain... drive slow, even with 1/8" of snow on the ground... I pulled out a car last night that went around a rather large sweeping turn a little too fast and found himself in the ditch. There was barely any snow on the ground, the amount so that after you drive on it you see the road where your tires are easily. On a back road or one less traveled he would have been easily stranded, even on this road he could have easily had to wait 10 minutes or more in cold temps, or 1hr+ in the middle of the night for someone to pass by.

For snow/cold temps... I suggest wool blankets at least two so you can snuggle up and hunker down until help arrives. Putting a towel on your front windshield (outside) helps too. I don't like the idea of running the car for the heater because carbon monoxide since not all cars are 100% air tight (Jeeps come to mind).

As far as warmth goes in my truck during winter I have.
- 2 Wool Blankets
- Extra pair of boots
- Pair of wool socks
- At least 3 beanies (I wear different ones and just have them there)
- GoreTex "boonie style" hat.
- Goretex pants
- Goretex jacket

I also keep my chainsaw with me in case I`m going home in a storm and trees are down. I also have a v28 sawz-all with a wood pruning blade for quick easy action if I need to cut something rather small hanging in the middle of the road.

I also keep 2 gallons of water x2 for misc usage (and potentially drinking) as well as 5-10 drinking water bottles.

A tow strap is also a very very good idea to keep on hand and shackles/hooks that may be needed too. A flashlight of coarse (I think you do this already).

I wouldn't use any flame inside the car. If you NEED a wire do it outside... however wool blankets and your 'snow gear' all on you in a car should be plenty warm to stay toasty through the night even in very cold temps. Some people even leave a sleeping bag in their car all winter just in case. Never hurts if you have the room.

We go "Snow 4-Wheeling" in our Jeeps during blizzards and "plan/prepare "to get stuck and spend the night... If you go prepared for spending a night or two then you will be ready to wait out a storm or until help arrives.

Another thing that may not fit in a car unless you get a collapsible one is a shovel. Often times in the snow simply removing the build-up in the front or rear (depends on if you are rocking or your plans to go front or back) is all you need to free your stuck vehicle.

Remember in snow if you are not making progress moving STOP do not dig a hole and sink the vehicle up to the frame. Rock it back and forth (From drive to Reverse) until you can get far enough back (or forward) to propel yourself out of the rut you just made. A good idea is to flatten out the rut too with the shovel so you can get out easier. I did this recently in my own driveway after getting semi-stuck.

Not to complicate things more but if you had brake stands with rocking forward and back, and also staying on the brakes while moving and turning the wheels side to side that often helps. There's a lot of little tips and tricks that really help when driving / stuck in the Snow. #1 tip... go slow, don't turn the wheel to much, and don't over correct. And recently I saw someone FLOOR IT and then catch traction and fly off the road on the OTHER side... So, know the traction in front of you too

I hope that's not overwhelming.