You'll be fine! And I hereby give you permission to slip off without saying goodbye if you need to. Just follow up with a note or call saying you had a great time and the host was so busy being fabulous that you didn't want to interrupt.
If it were me, I would also take my own AF drinks, ones that I like, so I know for sure that I won't get there and go "nothing to drink, guess I'll have a glass of wine."
whatever works!