I am here now for work and totally love Savannah! I took a couple of hours off to witness some of the craziness that is SPD here and:
1) if you come next year, look for the CAT, the Chatham transit busses that shuttle people from outside the Historic District in and out for the parade at least. I took a shuttle from the Savannah Mall and it was great to not have to worry about driving in the craziness, not that I would have found a parking spot
2) the crowds are enormous. I have no other word for it. Trying to get across a parade route street is impossible once the crowds start
3) I got a little tired of the actual parade and the crowds after about an hour and walked just one street away from the parade route and DURING the parade at least, it was empty all over. I easily found a place for a beer in my favorite tiny Irish Pub (O'Connell's on Drayton St) then easily found many spots to have lunch since the parade crowds were still largely intact.
4) if you go next year, keep in mind that its knat season here so bring bug spray
5) I hear its nuts down town right now (7PM) and my hotel way out on Abercorn is already full of drunken partygoers coming and going so without seeing anything after about 1PM I have to guess that its a madhouse on River Street. The open container rule here is a huge novelty to the out of towners !
I copped out due to my early morning work responsibilities and ate dinner at Tangerines, a fusion/sushi place out on Abercorn and it is WONDERFUL! If you are in town and don't mind the drive, head there or their sister restaurant called Ele on Wilmington Island. I can't wait to come back to my favorite city and eat again at this place!