Don't think this qualifies for winding down, but you may find interesting: https://www.sobpedro.com/
Charleston SC is very nice but further from 95 than Savannah.
Could detour a slight bit up to Raleigh NC
Could detour significantly more after Savannah and go up through Charlotte to I-81 and stay away from I-95. Much more scenic trip. Roanoke VA could be the final stopping point.

12 hours driving divided into 4 hours per day is a big big best case. So much traffic on that route.
Richmond to Dulles is a 2 hour drive in good traffic so if that is your final leg you will be putting in more hours the two days before. Raleigh might be a better point to stop.