We've driven down many times from New England (1300 miles each way) and have done it both ways. We are not taking the same route as you but our experience on I-95 going down the east coast are as follows:
1) We've never made good time and arrived hours ahead of time. There's at least one major traffic jam (and I'm not talking about driving through a metro area at rush hour. More like a lane closure due to construction or an accident) There's also this phenomenon going through the southern states that drivers stay in the left hand lane and never pass the vehicles on the right. They pull out and drive along side the 18 wheelers. They don't pass and they won't get out of the way. I don't get it!

2. If you are planning on staying overnight in a hotel and you have no reservation, you need to stop EARLY-like around 5 or 6 p.m. Or try to anticipate how far you will be driving on the map and call ahead that afternoon to make a ressie. We got stuck in an icky hotel one time because it was the only room we could find at 10 p.m.
3. We usually reserve ahead of time, like weeks ahead of time, partially because I'm an OCD planner but also because we have kids and do not want to get stuck in some strange area with no place to sleep. Then again reserving ahead of time may not be a big deal coming from the midwest. But we usually leave on a Friday and Saturday at the beginning of major holidays and there's a mass exodus of New Englanders all thinking the same thing-Florida here we come!! So you also need to consider when you will be traveling. Is it a busy time of year for traveling on the routes you will be taking?
We are going again mid July this year and there's no major holiday when we leave on Friday night so we're hoping the traffic won't be so crazy