I'm on the north fork for the next week myself. If you have the time to cook, get some fresh catch at Brauns seafood in Cutchogue and cook it. Peconic bay vineyards is right next door. Live music, wine.
A Lure is a good restaurant in Southold on Goldsmith inlet. Also try the north fork table and inn. Supposed to be good, but I haven't been yet.
As soon as I figure how to post a picture from an iPad, I'll put one up of my view of the bay. Georgeous this AM, great breeze yesterday. Living a dream.