Well, I answered my own question this weekend. A buddy and I left Friday at about 12:30 and it was a comfortable 16 degrees. We crossed the border at the NEXUS only Whirlpool Bridge then the 219 to Olean NY, 44-144 through Coudersport and Renovo, then the 120 to Lock Haven and 220 to Williamsport which was our base for the weekend. It was pretty dark from Renovo to Williamsport but a really bright full moon helped and gave the evening a cool vibe.
We took the luggage off the bikes for our Saturday ride as we were coming back to Williamsport at the end of the day. We explored Centralia which was pretty neat. The riding roads aren't quite as good as a bit farther west in PA but it was more about seeing the ghost town. It was about 6 degrees when we left in the morning but was a balmy 15 in Centralia. We came across a drag strip near Centralia so pulled in and watched the races for a while. Mid afternoon it began raining quite hard so we just headed back to the hotel for some beers. It continued all night (the beers and the rain).
Sunday morning was clear and 5 degrees. We slabbed it on the 220 and I80 to Snow Shoe then hit the best roads of the weekend up 144 and 44 to Coudersport. The heated jacket liner and gloves really helped and I was really comfortable which made the riding enjoyable. From Coudersport to Buffalo we were riding in the rain but it cleared up once we hit the border.
So, the road conditions were great with no leaves to worry about. The very light traffic in the area was even lighter than usual and we didn't see one cop in Pennsylvania. As some of you suggested, the only issue was the cool temps but if you're prepared and geared up appropriately touring in PA at this time of year can still be a blast.