I went to a wedding sober last year and it was good! Plus I looked decent. No weary, tired looking, reddish photos!
The coping mechanism that worked for me was three fold:
1. Always have a drink in hand. Mine is lemonade or cranberry and lemonade.
2. Keep occupied with the least drunk people in the room. If you hang out on a table full of drunk people it's not going to keep you exactly stimulated!
3. Go outside. I went outside three or four times during the evening once the meal was done. Spoke to people that were smoking and got some fresh air as it was on the seafront.