Hi Amanda, and welcome to planDisney!
Congratulations are in order for your family, I see! You are about to create some life-long memories when you guys visit
Walt Disney World Resort.
Unfortunately, regardless of size and dimensions, stroller wagons are not permitted at the theme parks. I understand this may be a disappointment, especially when you have to figure out how to maneuver with your three babies.
I do not know the ages of your children, but
rentals strollers are available to rent at the theme parks and Disney Springs. There are single and double strollers available, and the cost to rent a stroller can be purchased daily or for the entire length of your stay. If you want access to a stroller outside of the theme parks and Disney Springs, the Scooterbug dot com service comes in handy. The company will deliver the stroller to your resort before you arrive and will pick it up on the day of your departure from Bell Services.
Please let us know if you have additional questions.
Have a magical time!
Raquel