I'm with you bluegem,
I to have wedding on sat week where all my friends will be there and all will be drinking.
I to am driving and not really looking forward to it, cause it can be a long day times when all around you is getting plastered.
As others have said have a escape plan.
I done few weddings in past other times I was trying to get off it,and they weren't to bad, eat plenty is what I done. It is hateful that we can't be normal like the rest but that's just the hand we where drawn, we just have to accept it. Plus we won't have to suffer the hangover that they all have to face.
All the best with it