Reddit mentions of 3 in 1 Survival Light--Dynamo/Hand Crank, Emergency Zone, No Batteries Required, Emergency AM FM Radio, Mobile Phone Charger

Take it from a Montanan (we have long, lonely roads and plenty of snow). This is in order from "must have" to "if you have room". Not necessarily complete, but all I could think of atm.

• light source, such as a light or lantern, preferably one that does not need batteries. Even better if it's a light/something else combo. (examples here, here, and here)
  
• radio (see above)
  
• spare cellphone battery or battery charger (see above)
  
• military-style shovel, get it at an army surplus store, they can work as a shovel, axe, saw, etc.
  
• ski suit, one that you can pull on over other clothes
  
• energy bars, keep them in the glove compartment and change them out when they expire
  
• reflective tape
  
• tire chains
  
• gas, in a proper can
  
• gloves, or better yet mittengloves
  
• travel pillow, the kind that wraps around your neck so you can sleep sitting up
  
• a book, preferably full of short but interesting stories (examples here and here)