I've been there (Menemsha) by land years ago and remember what a nice small attractive harbor it was. I ruled it out for a stop though thinking day only.

The choices for anchoring overnight are limited on MV so any future options are nice to know.

We also stopped at Tarpaulin Cove last visit down and found that to be a very nice stop to swim and enjoy the beach waiting for the tide change. It really roars through there and makes no sense to buck the current.

I was thinking it too(Tarpaulin) was a potential overnight in the right weather.