We are visiting in June and this tour is high on our list to do. I know I can book 30 days out and there are only 15 people per tour, which isn't a lot. There are 4 of us in our party. So I was wondering if anyone has ever called to booked and not been able to because it was filled. We are limited to 2 days that we can do this and I'm afraid there is a possibility won't get in. Thanks.