Hmmm...tough call this early.
October typically is a slower time of year but this past year, it was very busy around the middle of October due to a big press event announcing the opening of Mission Space and Mickey's Philharmagic. I think this happened 10/9- just before Columbus Day weekend and seemed to carry thru the weekend into the next week.
We were there 10/21-27 and thought the crowds were OK- regular October vacationers still commented on them being larger than a typical October- but nothing like peak season. Most of the wait times seemed to be less than 30 min and some not at all.
Regarding
MNSSHP- We attended that on Sunday 10/26- again, not bad- walked on to most rides, no problem getting a space for the first parade and only needed to do so about 30 min early and had a practically spacious spot on Main Street for the fireworks (compared to the Sat night before where we were shoulder to shoulder in Main Street for the regular fireworks).
When I was invenstigating my October trip, these boards were great and commented that the Sunday MNSSHP dates are often less crowded because you don't have so much of the 'day traveler' factor since kids have school on Monday. Fridays are high attendance and of course, Halloween itself is crazy and was sold out this past year.
MNSSHP was a fun event!
Hope this helps.