There was a thread recently concerning the crowds just AFTER Labor Day, which everyone seemed to agree that the crowds are very low, and several described it as being dead. I tried to find it so I could post the link, but I didn't have any luck. I think I've heard that Labor Day weekend can be crowded, but I'm hoping someone can back me up on that. My DH and I are going the week after Labor Day, so I hope everyone is right about it not being crowded.
Gook luck getting the answer you're looking for.
-Laura