You can do it! Make a long long list of all the sober wonderful things you can do on holidays, I'll start (I'm going on holidays in August and it's a big deal to face it sober).
Waking up without a hangover and getting the best sun-lounge chair (or breakfast before the rush, enjoying time alone reading, watch a sunrise, meditating, or REALLY sleeping--when you're hungover you're not truly sleeping in and relaxing)!
You know you can do it, be prepared and practice, don't let doubts creep in.