Sounds about right. We left DC on June 24 headed south, and got to Daytona on July 15, travelling strictly on the ICW. We lost several periods of 1 to 3 hours for bridge schedules and in some cases waiting for higher water at the usual trouble spots. But we were also off the hook before sunup (once there was light enough to see), and some days we pushed to within 30 minutes of sunset, which I don't recommend unless you know the anchorage is going to be ok.
You get a lot further faster going outside, but my wife has never stood a watch before, or done any night sailing, so we decided to stay inside. I don't think we could have done it any faster. Hunter 31 with about 27' at the waterline, with a 23 horsepower Yanmar. We averaged about 5.2 knots.