Congrats! You'll love the Fort for Halloween!
Just FYI, but if you're looking to book next year to be there in time for all the Christmas decorations/happenings, best bet is to book later in November - ideally Thanksgiving week or later.
MK gets decorated in time for the first
MVMCP (last 2 years this was 11/10) - exception is the big tree which in recent years hasn't been going up until after the Christmas parade taping.
This year HS was also decorated in time for the 11/10 opening of Osborne light - however this was earlier than the previous year when they didn't start until the day after Thanksgiving. Not sure what future years will bring.
Everything else generally goes up at varying rates throughout November, with it all being in place for the big holiday kickoff the day after Thanksgiving.
This past year AK and EP were decorated about a week after MK and HS (around the 14th-ish). DTD was done fairly early in November. We left on 11/20 and saw hardly anything in the resorts. From what I gather, those decorations started going up the weekend before Thanksgiving - although not sure about GF, as the gingerbread house as open sometime mid-Nov.