Crowds during the week were fantastic! I've been several Octobers in recent years, and we much preferred the crowd that first week of December.
To give you an idea, on the Tuesday after Thanksgiving, four of us walked into Trader Sam's at Poly and the place was more than 2/3 empty (it became fuller as the evening wore on, but there were still seats available when we left). The bartender said it was the slowest week of the year. We went to AK on Wednesday and basically walked onto Expedition Everest, which we often single ride if that option is available. Didn't need it this time. Dino and the river ride were down the day, so we just kept going onto EE. We hit Frozen on Thursday morning after our breakfast ADR at Garden Grill...there was a 30 minute wait for the ride about 45 minutes after park opening (that was about the best wait time for Frozen that week...some rides just have long wait times no matter what). We were staying at BC and had park hoppers, so we went to Epcot almost every night and had nice, low crowds. Left dinner after Epcot one night and noticed a 30 minute wait for Soarin', so we hopped in line. Overall, we found wait times for most popular rides were reasonable during the week...Frozen, Dwarf Mine Train, and Toy Story Mania were the exceptions (though each had lower wait times early in the morning).
Things got much busier on Friday/Saturday (the second weekend after Thanksgiving Thursday). Cheerleaders were everywhere! But overall, the crowds on the weekend were still more manageable than weekend crowds I've experienced in October.
The weather was also fantastic! Highs in the 70s or 60s with no humidity, and lows were in the high 50s a few nights.