Hi Katie,
Thanks for visiting the Disney Parks Moms Panel. This is a great question and with the ages of your children, I can see your dilemma.
I am a big fan of using a stroller in the parks as long as possible. I love having the option of letting my boys nap or just relax when they need a break, especially if we stay out past their typical bedtime. It is also very convenient to have a spot to carry bottles of water, bags and any other items we want to have in the parks.
My suggestion would be to bring or rent a single stroller from a vendor like Kingdom Strollers for your 4-year old and if your older child gets tired at the end of the day, you can always
rent a park stroller if he or she meets the height and weight requirements.
If you plan to build a mid-afternoon break into your days, you may find that a single stroller is all you need.
Please le me know if you have any other questions, Katie. Wishing you many magical moments on your family vacation!
Happy planning,
Andrea U.