You will be arriving on the 4th which is just right after Halloween, so depending on how long of a stay you are having, I would probably think that the Halloween Decoration will still be up, and then the switch out most likely would start on the sometime the next week.. As well you might be on the tail end of Food and Wine over in Epcot...
As a Previous Poster stated, the Resort decoration will go up closer Thanksgiving...
Normally we would just look at the dates for Mickey's Very Merry Christmas Party, the Decorations for sure will be up in MK, with that said..... With that said, Due to Corona Virus, which caused the cancellation of all Hard Ticket events last year, it really is up in the air if this year there will be a Christmas Party or any other hard ticket event...It really is just a wait and see for those events...