I keep a wine stopper in my toiletry bag. It’s so small and light, and always comes in handy when I'm traveling.  Most places have bottle openers, or maybe the hotel front desk has a corkscrew, but they never have a wine stopper.  

So finish that drinkable bottle of wine the next day or throw it in your tote without worrying. Until the screwtops take over, you'll always be prepared!