Headlamp AND flahlight (Preferably the biggest mag-lite you can get so you can beat people with it if you have to)
Stove With extra fuel- I'd go with a white gas stove for this purpose, since they work much better in the cold. I find my Gigapower (uses butane canisters) doesn't really work down below 20 degrees unless I warm up the canister in my bag.
Warm sleeping bag- I would go with something around 0 degrees, but thats just me personally, I'm a pretty warm sleeper and have had LOTS of experience sleeping outdoors in a variety of different bags and temperatures so I know just by looking at the loft if its warm enough. Dont use a bag thats been compressed for years and expect it to be as warm as it used to be, They lose loft after a while, synthetic faster than down.
Extra fleece or wool blanket- something you can throw over your sleeping bag without it weighing it down and compressing all its loft. Staying warm depends on trapping dead air. If iyour sleeping bag is all smooshed its not going to keep you very warm
Space blanket for emergencies
Clothes for sleeping in.
Gameboy with pokemon blue
Some heat packs you can throw in your sleeping bag
A closed cell foam sleeping pad, plus maybe a cheap open cell for padding or a blanket to lay on (open cell doesn't insulate very well, so a closed cell pad is for heat retntion)
Enough food you can eat for one day longer than you are plannign to stay, including food you can rely on if your stove breaks. High calorie shit. If you are cold, you would be surprised how much warmer you will be after eating a snickers
Lots of water. (keep your spare blanket over it so it doesn't freeze super fast)
A piss bottle so you dont have to go outside to pee.
A teddybear you can hug if you get scared
Lots of weed.
A pillow
Cell phone charger
Batteries
A shovel to dig yourself out in the morning if its dumping.
Toothbrush + paste (Ben Franklin am I right?)
Thats all I can think of right now. You shoudl also obviously keep an emergency kit in your car (jumper cables, first aid, blanket, gloves, hat, maybe some granola bars, etc). Keep a window cracked, dont cook in your car (carbon monoxide zomg), and lock up your skis. Also, don't run your battery empty, this seems like comon sense, but if you woke up in the middle of the night freezing and wanted to turn the car heat on and your battery was dead, it would be a major bummer. The biggest part is finding a place where you can crash without police or locals bothering you. If you do you are golden.