Soggy is not noted for its NYE party. I am not even sure they are open that night. The famous party is at Foxy’s in Great Harbor JVD. It is a total zoo and you almost need to get there a day or two early and camp on a FCFS ball. You did not mention if this is a crewed charter or bareboat. That makes a difference. A larger crewed boat will likely have a dinghy that can open up other options to overnight and run people to the party. Personally I would get there a day early and put the boat on a FCFS ball in Little Harbor or Diamond Key and cab to the party.
As far as beaches Anegada has the best but there are numerous other great places as well. You are however going when both the Christmas winds and North Swell are a factor. You really need to play it by ear and see what the weather brings.
.
