Kudos to you for making serious preparations. Many snowmobilers don't seem to realize how fast they can get into deep, deep trouble.

Hot liquids, quickly, get you back on the right track. Instant soups and such provide core heat, electrolytes, and hydration. Not to mention the psychological boost. I have broken up some of those instant Ramen-type noodles and added them to instant soup to get a quick carb hit. A small, hot stove would certainly be a blessing in some situations.

For sheer blowtorch calories, SPAM probably isn't a bad choice provided you can get it down. A jar of peanut butter would also pack a punch. Match one of these up with some dense crackers and you'll get through. (IMO you'll be highly motivated to avoid being stranded if SPAM is your primary food source.)

Freeze-dried backpacker meals are a little more fussy since they need liquid water. Note that they will rehydrate, somewhat, with cold water though they won't be nearly as pleasant to eat. The light weight makes them easy to take along though, and that's important.

Let us know what you decide on.