I grew up right along that route (Elkton MD/ Newark DE), and would not try anything like it in 2 days. And I did a 180 mile lightning tour of CT and MA in 31 hours in April.

That is the densest urban stretch of North America. If I were to do it, I'd cut down and over the Rt 50 Bridge and over to DE. (not sure about getting a bike over that bridge on a bus or something.)

Then the Lewes-Cape May Ferry and up the Jersey shore, and another ferry from one of those towns on Sandy Hook Bay in NJ up to NYC.

There is a Nat'l Geographic scenic ride up route 9 in Delaware. Nice riding. Used to do my first MS150s there when I was 12. Also, if you can get over to the Eastern Shore, a ride up 213 is also excellent riding.