Hi,
As with any question about crowds, you are likely to get the following two posts among your replies:
Post 1: We went at that time last year and the crowds were great! We walked onto everything!
Post 2: We went at that time last year and we will never do that again! The crowds were horrible!
But...the bottom line is...October crowds are quite manageable. And at all times of year, weekends are busier than weekdays, and holiday weekends are busier than regular weekends.