Erie Canal in October:
If you do it during peak colors, you'll have an amazing view. The Hudson Highlands are spectacular. October weather in upstate NY is usually very nice the first half of October. We did it in 2005, leaving mid October, spending Thanksgiving in North Carolina. However, by the time we reached Florida, my wife insisted that we buy a cabin heater. We didn't thaw until reaching Miami on New Years Day.
Favorable windows for going offshore to speed your passage become fewer as fall/winter progresses. You'll also be motivated to move fast and not linger to see the nice spots along the ICW.
Still, hundreds of cruisers do it late every year, not arriving in Florida until Christmas. Cruising boats with enclosed cockpits have it much easier It depends on your tolerance for cold. We've become completely intolerant..
Happy sailing