I know only losers end up with this thing called "leftover champagne," but -- if due to extreme circumstances, you find yourself with some "bonus" bubbly, you can make it into a very refreshing and tasty granita.
Photo by Mari Liis.
Actually, you can make a granita with any sort of wine or beer, not just sparkling wine. Simply combine a cup of whatever booze you have leftover with 1/4 cup plus two tablespoons water and three tablespoons of sugar. Stir it all together, pour it into a shallow baking dish, and put in the freezer until it's just barely frozen. Beat it up with a fork a bit, so you have lots of icy crystals, and pop it back in the freezer. Once frozen through, scrape into coupe glasses for serving (if you wish to stick to the champagne theme), and enjoy.
Après Party Granita [Food 52]