Congrats on getting that pound off, Bizi!
But it sounds like you are, at least in part, disappointed that you lost it and will not be drinking pre-vacation.

The first time I was on the South Beach Diet, I plateaued a couple of times. When I went to a couple of forums, they said a cheat day could restart weight loss, and it worked for me. But that's a strict diet, so IDK if it would work for you

I'm sorry that you aren't ready for your trip yet
Will you have to spend a lot of time at your MIL's house? I know that you find that really stressful.
You can bring your stevia birch beer and root beers with you to help you stick to whatever alcohol limit you decide on.

I'm glad you got the AC on your car fixed. It's hot out. The trip there would be very uncomfortable otherwise. It was very smart of you to think ahead.