I vote for October. I know that's a while away, but that would give everyone time to make plans. Savannah is beautiful in October! River Street is decked out in pumpkins, scarecrows, and chrysanthemums. At least, it was the last time we went at the end of October. The weather is great then, too.
I also suggest we stay at the Hyatt. It's right on River Street, and the back elevator deposits you slap dab on River Street. That means not having to find a parking place on RS - not an easy task. In fact, you can walk to just about anywhere you might want to go and leave your car at the Hyatt.
When we've stayed at the Hyatt, we also found that their restaurant, Windows, had pretty good food that was a lot cheaper than most of the restaurants on RS. I think Windows is open for breakfast and lunch.
Feedback?