I suppose you're right on the protection from the north but it's so open, I don't even think of it as an anchorage(maybe I should check it out though)

The worst winds I've seen have been southerly as they clocked through Northeasters here.

Then again, last summer we were sailing around Marthas Vineyard when hurricane Earl was predicted to hit the area. At one point we were in the direct hit zone. It wasn't fun. However, they were scrambling in our home waters(also in the predicted zone for some time) in Maine as well. My mooring in Rockport was being asked for to ride it out. (Rockport is wide open to the south as you know).

My feeling is I'd move my boat to Pulpit (as someone posted) Harbor or Perrys Creek just around the corner from Southern Harbor. Just a bit over an hour, they're my short notice holes.