Watkin's Glen is a neat place to stop (for a night or two) and walk the gorge in the state park. This would probably be best if taking I-86 to I-88. (Maybe that's something you've already done in the category of of the finger lakes.) The glass museum in Corning is also well worth a few hours to visit; it's rather more interesting than it may sound like it ought to be.
If you time things correctly, seeing some (or all) of the Little League World Series is a lot of fun if you're into baseball. Camping and RV parking is not always the easiest to come by in the area during that time, though there are some area residents that offer dry camping in their back yards or other land, some fairly close to the fields. The games themselves are free to watch. It's generally mid-August when the world series happens.
