The best places to have breakfast is in the EPCOT resorts. Yacht Club Gallery, Tubbis (Dolphin), Fresh (Dolphin) Cape May (character) and even the Boardwalk Bakery.
I'd have breakfast in my resort, I don't think it's worth the walk through EPCOT just for breakfast. If you MUST have breaksfast you can take a resort bus to MGM and then take the boat to the Boardwalk area.