Yes, my recommendation today will be of earth-shattering importance, ha ha: use the hotel's glassware when provided.
You'll cut down on one more plastic bottle going into the landfill (because, really... you're on travel, are you really going to be able to recycle that?) and I know we've all seen that 20/20 special on germs, but.... Let's live a little. Drink from the glass. Win-win.
Pocket: 6, Planet: 9, Win-Win: 23