Hi there, Caroline!
We did this exact same thing on our last Walt Disney World Resort vacation. We enjoyed a fabulous meal at
Topolino's Terrace before playing the day away at EPCOT.
Caroline, since your breakfast reservation is so early, you will most likely be unable to park at EPCOT. You see, while the parking lot grants you access to the front of the theme park, the
Disney Skyliner is actually located at the back entrance to the park, called the International Gateway. If the park is not open, which it most likely will not be at such an early hour, you will not be able to walk through the park to get to the Disney Skyliner.
You have two main options. Your first option is to drive to
Disney's Riviera Resort. Once you are done with your meal one adult can take the car to EPCOT while the other adult takes the kids on the Skyliner. This is what our party elected to do, specifically since my husband is not a huge fan of heights, he was happy to meet us in the park.
Your second option will be to take a taxi or a rideshare service to Disney's Riviera Resort. You can then head over to the parks; however, you will need to be sure that you arrange transportation for the trip home as well.
If you do not mind taking a round-about way to the parks, I do have a third option that you may be interested in.
Disney's Hollywood Studios generally has an opening time earlier than that of EPCOT. Depending on the time of your breakfast reservation, you may be able to park at Disney's Hollywood Studios and take the Disney Skyliner to breakfast. Again, you would need to have a reservation late enough for the Disney Skyliner to be running to Disney's Riviera Resort from Disney's Hollywood Studios. The Disney Skyliner generally starts running about an hour before the published park opening time. Once you are done with your day at EPCOT, simply hop back on the Disney Skyliner to get back to your car at Disney's Hollywood Studios.
If you are planning on going with option number 3, just be sure you keep an
eye on the time and get back to your car before Disney's Hollywood Studios closes for the day.
I hope that this answered your question, Caroline!
See you real soon!
Sarah B.