I freeze it in ice cube trays, too....but I usually buy the same brand of wine, so I use the cubes in the next bottle of wine. Chills the wine without watering it down.
get a tray of ice cube makers, and pour the rest of the wine into each seperate hole. then let it freeze, and next time you have guests round and have white wine or the opposite wine to the ice cube wine, put some into the glasses! its smart, people will wanna know how you did it, and it uses it up aswell as save money and tastes so nice!
Freeze it either in a freezer bag or an ice cube tray and next time a recipe calls for a glass of wine, use this instead of opening a new bottle. I have red and white 'wine slushes' in my freezer.
I don't normally have any wine left over from anything - but if you've mistakenly bought something you really can't drink I would agree with the freezing in ice-cube trays. They can then be added randomly to your cooking - or to a jelly mix - add some fresh fruit, set in glasses, makes an interesting combination for a dessert. You could put a squeeze of honey into the ice cube tray before the wine - could almost make it palatable - in which case drink it anyway with the honey added!