Dave, never been to Shelter Island, let alone fished it. But, it's in the bay and should be just about perfect for the long wand and a light schoolie stick.
The 8-1/2' BD would be useful at Montauk under calm conditions---but, I think the wind will be blowing E or NE thru the weekend in the 10-15 kt range, and those aren't the winds for flat surf anywhere on the north side. But, you definitely want to drive up there and salivate for a few minutes
Yep, Range Rover season opens this weekend. They'll be out there in force. Probably your best shot is to take the ferry to Orient Point from New London rather than brave the LIE follies. Nice hour and a half ride and you can eyeball the structure at Orient as your docking, and get a look at Plum Gut and some of the nice stuff the boaters get to play around in around Plum and Fisher's Island. Somewhere in that neck of the woods, Bob Rochetta boated his 76.