Hi Sara!
Thank you for visiting the Moms Panel!
The weather at the start of November can be very nice, definitely fine for swimming. The average high/low temperatures for November are 79/59, with an average rainfall of 2.3 inches. Weather, of course, has it's own temperament but hopefully it will stay lovely and warm for you. The crowds in November are usually at their lowest, until Thanksgiving week - so you should be able to enjoy the parks at their least crowded.
I attended Mickey's Very Merry Christmas Party last December, and it was such fun! If you love the Magic Kingdom, would like to see snow on Main Street, experience your favourite attractions, and so much more -
see full details here - I would definitely recommend it. It is a lovely party!
If you have any other questions, please come back and ask me - I would be happy to help you plan your magical vacation!