Here's something to think about. Today is October 15th. In Philadelphia, PA, which the route passes close to, it's about 48 degrees with a cold rain. Winds are expected to strenghten to 25 mph. Rain is forecast through Friday and may possibly last until Sunday. And it's just the beginning of Nor'Eatser season. For the last few years I have done a club ride that starts near New Hope, PA, which the route passes through. It's been at or below 40 degrees at start time each of those three years. Now think of what it could be like on northern PA/NJ, NY and MA if you were to choose the late departure date.
So....It all depends. Would you rather have heat and humidity or the potential for cold, wet weather.