Boo to you, Christopher!
Disney's Fort Wilderness Resort really gets into the spirit of the harvest season with many of the onsite guests decorating their campsites and participating in a Golf Cart Parade during the evening of Halloween. And you are correct,
Mickey's Backyard BBQ dinner show got in on the holiday hoopla last year too! I was unable to confirm at this time that the characters and band members will once again be dressed in their spooky best for this year's cookout however, I was informed to expect information on this to be released to the general public around the end of the 3rd week in September.
I suggest that you monitor the main pages of the
unofficial websites: www.mousesavers.com and www.allears.net as these resources are known for working diligently to provide accurate, up-to-date information on the latest and greatest Disney travel experiences. In the meantime, you might enjoy checking out this
Disney Parks Blog entry about last year's foot stompin' fun during Halloween. Please keep in mind that it's always recommended that guests arrive early, and allow extra time for transportation from the parks to the resorts, especially during unique special events.
Wishing you a magical Disney vacation this Fall and please feel free to send more questions my way prior to your trip!