Hello Charles! Planning a visit to the Walt Disney World Resort with grandchildren is a great idea! Your grandchildren are so lucky!
When it comes to deciding on strollers, it is good to know what will make your grandchildren most comfortable. My oldest son is just one-year older than your oldest grandchild. He has no problem navigating the parks for several hours at a time. Just be sure to give a sit-down break from time-to-time and stay hydrated! June gets hot in Florida! Your five-year old might benefit from the stroller as the parks can get to be a bit much for their little legs!
I recommend
renting strollers at the Walt Disney World Resort. This will save your family the trouble of traveling with a stroller. They can be quite bulky during travel. There are single and double strollers that can be rented during your visit.
Charles, since you will be traveling with your 5 and 9 year-old grandchildren, I want to recommend considering a
Character Dining experience for your family. Your grandchildren most likely have favorite Disney Characters! Having the opportunity to meet those characters, during a delicious dining-experience, might be a dream come true for your grandchildren!
I hope that you and your grandchildren have a magical vacation to the Walt Disney World Resort! Please come back to the Disney Parks Moms Panel if you have any other planning questions.
Hakuna Matata! Jonathan G.