Your average passenger liner is over 15 stories high from the surface of the ocean. If you fall off, I don't think you need to worry about what you need to do next.
If you get stuck in your car in the snow, STAY WITH YOUR VEHICLE!!! Hypothermia makes you delirious and you can wander the wrong direction and freeze to death. Your vehicle is also a LOT easier to locate than YOU are.
Your average passenger liner is over 15 stories high from the surface of the ocean. If you fall off, I don't think you need to worry about what you need to do next.