We were late Oct early Nov family ourselves and last year did the last week of August and to us, NEVER again! lol I was dying it was soooo hot, however, I did not plan on it being that hot that you couldn't even enjoy the pool or take pictures, yuck.....and we didn't get a drop of rain which I would have LOVED!
If I were to go again that time of year I would invest in one of those misty cooler thingies....and bring lots and lots of tank tops to change into. Also, I would bring lots and lots of sunscreen and a hat! I must say that there were some perks go going this time of year, namely that the parks are practically empty (with the exception of the Peter Pan ride, go figure) and there are lots of places to cool off in too. If I didn't have little ones (4 year old twins) and had to push a stroller around then it would have been a lot easier and more tolerable for me. My sil loved it and the kids (with the exception of the little ones) didn't seem to mind it either because they just soaked themselves constantly!
Anyway, it's still Disney and it's still lots and lots of fun, just be prepared that's all.