Thanks for the responses. I thought it was strange so much already booked this far in advance.
We will be driving back from Florida, our last trip there, and I vowed I would visit Charleston this time on the way back (we have already visited Savannah before). I am desperate to visit Charleston!
I have provisionally booked the Residence Inn downtown/riverview, although I know this is not walking distance to the historic area. I just want the whole day on the Saturday to explore. We will be leaving Sunday moming anyhow, if we can get out with some of the roads being closed!
Thanks again for the info :o)