Hiya Zoe - welcome to planDisney!
I'm so excited about your visit to the Walt Disney World Resort in just a few short months! The magical
Walt Disney World 50th Anniversary Celebration will be in full swing, so be sure to plan extra time for all the new and exciting attractions, experiences, treats, and so much more!
I was able to speak to a Cast Member about your
parking question to get some clarification, and they informed me that while you should be able to park your vehicle in standard parking, it will be at the discretion of the parking attendant at the theme park entrance. The formal policy on parking currently lists the following as "oversized" vehicles: Shuttles, Limos, Camper Trailers, RVs, Buses or Tractor Trailers. As you can see, a 15-seat minivan isn't specifically listed, but if it is determined that your vehicle can't be accommodated by a standard parking space, you'll need to opt for oversize parking.
Luckily, oversize parking is currently only $5 per day more than standard parking. As an added bonus, standard parking at all four theme parks is included for Guests staying at a Disney Resorts Collection hotel. If you or anyone in your vehicle is a registered Guest of a Disney Resort hotel, you'll either have complimentary standard parking or will only need to pay the difference to upgrade to oversize parking.
Also, keep in mind that there is fantastic complimentary transportation to many destinations within the Walt Disney World Resort. From buses and boats to the classicly futuristic Monorail and new Disney Skyliner, you may not need to rely on your own transportation as much as you think!
I hope this helps your planning - please let us know if any additional questions pop up as your trip approaches!
Ryan J.