Snowed in? Make the best of it. (You DID stock up on tequila and limes, right?)
Mix all ingredients (except snow) together and chill well. (You don't want to melt the snow with warm ingredients.) Harvest the snow, and fold in the chiled enhancements. Spoon into your favorite festive glassware and enjoy your snowgarita in front of a stoked-up fire. Why not? The snowplows are nowhere in sight, and you won't be driving anywhere anytime soon.