Thanks for the responses!
My son is just turning 2 and weighs 29 pounds now so I began wondering if he will be too heavy for the pack n play for our trip in August. I'm not sure he will sleep in a pack n play anyway but was going to give it a shot if he isn't too heavy. I've read many posts about people using the pack n play for 2 1/2 year olds and no one has mentioned a problem with weight limits but I would think that many 2 1/2 year olds are over 30 pounds (my son is tall, but very thin and he is almost at the limit now).
I may try getting the bed rails and keeping him in bed with me or DH. Good to know that Disney will provide them. Actually, it wouldn't be a bad idea for my 4 year old either!
Thanks again to all of you for sharing your knowledge!!