It May!! I tried it with one adult and got the same results you did. In April and May there are quite a few dates missing!Does this mean the ship in completely full?
Right around the 60 day mark is when the bulk of the cancellations come. I would be checking daily (yes it's obsessive - but if you want to get a ressie) around the end of May and not stop checking until you get a room. I don't know if a TA will help you with the project or not, but it may be a good idea to check with one to see if they can waitlist you.August 28th 7 day - kids sold out!!
My brother and his family wanted to book also. What's the best way to find out about cancellations??