We generally go in Oct, and are leaving on the 10th for 10 nights. As @bailau said, often times we've stayed on a ball and no one came to collect. We've never had problems pulling into a field late in the day (as late as just before sunset) and finding a quiet place. In some fields we've been the only boat. In others we've been one of a half-dozen. Yes, we give up having everything open, but we're much happier with the no-crowd. If you like no crowds (and we don't get a storm) you'll love the BVIs in Oct.