I've always corked it and finished it off the next day. Opened bottles have never lasted longer than 2 days as I drink them within that time. So with me...I've never worried about preservation.
I don't really buy good enough wine for it to matter. A few days for white in the fridge, and one of the vacuum pumps for reds that don't get finished that night. That hardly ever happens, but its usually finished the next day.
