Hint: Stash at least two tubes: One to show all your friends—who will drink all your good beer—and one private members only stash.
Will it freeze? I’ve only had a few slushy beers. If the tube is buried correctly, the snow is an insulator from the much colder air. I’m sure there’s a chart somewhere with the exact temps in relation to snow pack and density. We didn’t care to find it.