We went mid-October one year (close to Columbus Day), and it was pleasant - until noon. The crowds at the MK were so bad that the wait was over an hour on most rides. It was nearly impossible to get a spot to watch the parade an hour in advance. I swore never to go at that time again. What am I doing now? Trying to decide whether to go in mid-Oct or mid-Nov. I never learn.
Blizzard Beach was nice. It got a little cool close to closing, but the crowds were tolerable.