I'm considering buying 10 day no expiration tickets for our upcoming trip, and just using 5 days, and saving the 5 for later. However, my DNephew is now 8, and may be 10 or 11 when we next take him. So if I buy the kids ticket for him now, use the first 5 days when he's under age 10, what happens to the extra 5 days when he's 10 or 11? Can he still use the ticket, or are those days lost? Would I be better off just buying him an adjust ticket now (it's only $29 more)?