There are a couple of ways to avoid the whole Baltimore Washington mess completely & retain some sanity while avoiding the area.
Both involve crossing 95 a little S of Wilmington, DE & either getting on 301 S across the Bay Bridge, no toll WB, keep following 301 S through Waldorf & on across the Potomac well S of DC & carry on to 95.
The other way is to follow 13 down the DELMARVA & cross the CBBT, an experience all by itself, to Virginia Beach to 58, nice ride, to 95 well S of Richmond. The CBBT is about 20 miles of bridge with 2 tunnels deep enough for tankers & carriers to go over your head.
Killens Pond SP, a little S of Dover, DE, open year round I think. Nice one 50amp & water. Kiptopeake SP, just N of CBBT, also year round.