You'll always be backwinded in Little Harbor. When I go there, and the weather is reasonably calm, I anchor just 'peeking out' at the channel close to the NE point (by the ruins of the Chubb house). You will avoid the backwinding effects of the high hills closer in.
You won't be backwinded in Great Harbor, either on the moorings or anchored along the southern shore, or the western shore towards Fisher Point. You could be backwinded if you anchor on the eastern shore, close in or towards Great Harbor Point.
Deadman's Bay isn't a great overnight anchorage in any weather, unless you're on a cat. On a mono, it's most often rolly.