Hi Tanya! Visiting Walt Disney World during cooler and less crowded months is a great strategy.
Of the three dates you mentioned, the first week of November would be the best time for comfortable weather with a low chance of rain. The park attendance levels in early November tend to be moderate and would be similar to what you've experienced in May. Depending on the timing of your visit, you may be able to catch the last
Mickey's Not-So-Scary Halloween Party or the first
Mickey's Very Merry Christmas Party (or both!) during your November trip.
The week after Labor Day in September is a fantastic time to visit if you want very low crowds, but the temperatures tend to hover around 90 during that time and it can be one of the rainier months. Early April tends to be a little more crowded than May, September, and November. The temperatures are warm and pleasant in early April, but in my experience, brief spring showers can be frequent then.
Whenever you visit Walt Disney World, I know you'll have a magical time! Come visit us again here at the Moms Panel if you have more questions! We'd love to help!