So far, I haven't needed to explain myself. I just order something non-alcoholic. If asked, I said "I'm driving" or "big day tomorrow" and no one blinked an eye.
Big test will be holiday and birthday parties where a big group of family gets together and the wine starts to flow. Oh, and yeah, those wine-tasting fundraisers that I have to attend because I'm on the board etc. Haven't crossed those bridges yet.