Something to be aware of... I know you are new to the boards, but I do not know if you are new to Disney World. It is not uncommon to travel at least 8-10 miles a day on your vacation. The ground at Disney is not all smooth like indoors, but is made to be "authentic" ground, so there are a LOT of bumps. Sorry if you have already considered this, but are you going to be comfortable walking that much, even with a rollator?
Before I started using a chair full time, I would use my walker or crutches at home, but I needed a wheelchair or
scooter for Disney World.
Again, sorry if I overstep, but I want you to enjoy your vacation!