Hi Sarah! 
A fall trip to see the mouse for five days sounds practically perfect! Balmy temperatures, a chance to eat your way around the world at 
Epcot's International Food and Wine Festival, and enjoy some Halloween fun at 
Disney's After Hours Boo Bash will create memories you can reminisce about around the kitchen table for years.
You are good to go with your tickets. A four day 
Park Hopper Plus Option gives you four days of theme park hopping and four "pluses". With your plus option, for each ticket day you are granted an extra. You may hit up the 
Disney Water Parks, play a round of miniature golf, and experience other sports related choices four times. Each entry into a water park counts as one experience, so if you leave for an afternoon nap and return for some evening intertube fun, that is two of your four pluses.
I live in a beach tourist town with an abundance of water parks, so I thought I'd seen every possible way to splash and slide. Then I saw 
Disney's Blizzard Beach Water Park. Entering this venue, you will feel like Belle seeing the Beast's library for the first time. The clever, whimsical theming, the towering 
Summit Plummet, the 
Tike's Peak water play area for preschoolers, and the best mini doughnuts will give you your most fantastic pool day ever. 
So much delight and fun is in your future! I hope you enjoy as much Mickey shaped food as possible. 
Elisabeth