Hello Stephanie!
I LOVE your question!!!! Based on the description of your perfect Walt Disney World Vacation, I would most definitely recommend booking your MAGICAL vacation in September! My family LOVES September because of the low crowds, cheaper prices, and FREE Disney Dining! It's like we are from the same family! In fact, if you book your Walt Disney World Vacation before May 18th, you can take advantage of
FREE Disney Dining from August 25 through September 29!!
Now, I will tell you that the temperatures in September can still be on the hot side. You can expect the highs to be in the upper 80's and the lows in the low to mid 70's. However, I really think you will be able to manage the hotter weather with all of the money you are going to save in September!
If you have other questions, please let me know!
Have a MAGICAL day!
Wes