We have gone about 4 times each of the last few years and we have only seen 1 snake, a black snake I think, during the May '09 floods. If any of you were there it was the wettest 2 weeks I can remember since I moved to Florida in 80. That is the only time I've seen a snake. Lots of other interesting wildlife - turkeys, deer, armadillos, etc. You should be fine.
We stayed at the ASMu in 2009 and saw one on the sidewalk and there are posts about seeing them at the CBR so I don't think it matters where you stay. There are snakes in Florida but I definitely wouldn't worry about it. Have fun!