You can still access Josh's prior year month by month analysis via his website. Go to crowd calendars, select a month from 2015 or 2016 and click. There will be a link to the month by month overview including month, cost, weather, crowds and events. While the info will be specific to that year, the general logic is still there.
Example from Josh's October 2016 information..
"October Crowds: Crowds are heavier in October than past years with domestic school schedules moving away from the typical long summer vacation, in favor of a larger number of shorter breaks throughout the year. That includes a week off in October for schools in the south, which feed Disney World attendance. South American attendance is also higher in the first two weeks, culminating in the largest crowds of the month over Columbus Day Weekend, from the 7th – 9th. Still, they won’t be anywhere near as bad as summer or other holiday weekends. If you are flexible with your dates, hold off until after October 15th. Epcot’s International Food and Wine Festival is scheduled throughout October, which makes Epcot busier on Fridays, Saturdays, and Sundays."
Just look at the days of the week these dates apply to and interpolate them for your visit, keeping in mind that Disney has added more days to parties and festivals since then.