Whether it is a good idea or not has a lot to do with your preferences. I say that between now and winter the sooner you go the better (once hurricane Irene has passed). Another factor to consider is that daylight hours will be getting shorter as well.

All that said it still might be fun if you don't mind some chilly weather. Personally I like that better than hot weather as long as it isn't brutally cold. It is a bit of a crap shoot, but chances are good that you might have mostly nice cool, but not freezing fall days with a few cold ones thrown in.

If not you could do all or some portion of the Southern Tier route, if you are willing to fly at both ends.