The week after the week of Labor Day can be somewhat quiet, as can the first 2 weeks of December. October is no longer by any definition "lowest crowd," due to the shift of many schools to fall breaks, plus the Columbus Day weekend. November also has Jersey Week, the Wine & Dine runDisney event, and Veteran's Day weekend.
However, the entirety of fall is high season for
DVC. The first weeks of December are in the top-demanded weeks of the year. Food & Wine books the monorail and Epcot resorts pretty heavily in the 11-month booking window. If you are renting DVC in the fall, good rules of thumb are that 11-month bookings are essential for monorail resorts and Epcot, and if you are trying to get a booking at the 7 month mark, an 8AM login is essential and your success may depend on if your computer is faster than someone else's. This year, for much of October, the 7-month booking window was quite fierce.