Hi, Carin!
I'm with you; planning is the way to go when you want a trip to Walt Disney World to go smoothly.
Because you're a pro at planning ahead, you are absolutely right to carefully plan the most memorable trip of all...your wedding day!
I think an outdoor wedding in October would be stunning, Carin. Temps will start to cool down a bit, typically getting cooler the further you move away from September. The average October high in Orlando is 84, quite lovely, really!
Regarding a wedding reception in Epcot's France Pavilion, I can't imagine a more elegant setting. With tables set up along the waterfront (aptly-named)
Eau de France location, you're sure to have memories and gorgeous photographs unlike any other. Keep in mind, too, that the Epcot International Food & Wine Festival runs throughout October, so imagine what fun you'll all have before your big day, should you choose to do so.
Send more questions as you continue to plan, Carin. I'd love to help you pick the most pixie-dusted plans possible!