Good for you - that is an excellent boundary.
Personally - if this new boundary (about stopping for wine) is surrounding a visit things could get so stressful. I think I'd say ahead of time that you no longer allow alcohol in the house before he gets there.
I can't imagine going from airport to house, refusing to stop at the liquor store, get home, assuming he doesn't have a car, and then what? He goes nuts without alcohol, he gets riled up for you to go get some? I'm not sure how that would play out.