snowmobilers already have a shovel, and generally snow gear atleast good for daytime weather. Probably the situation will activate a search and rescue team, and most likely the "victims" will not be out all night, but they will need to be able to contact rescuers. I'm thinking a sailboat whistle along with the flare gun. Many high intensity flashlights or other LED flashers may be helpful. Id choose a thermos of hot coffee or chocolate over a stove and pot.