When we leave the Boston area to go south, we usually leave around 8PM, getting to NYC at midnight. We will take I84-I91-I95 to the GW. Road conditions are not bad, the usual temporary lane closings due to summer repaving season, until you get around NYC. Taking I287 eliminates most of that. Tappan Zee tolls eastbound only now that they have implemented cashless toll, but they will go back to westbound
when the new bridge is complete. Also there is the toll on the NYS thruway section of I287 if you don't get off at the GSP.
Two years ago I84 was a mess going thru PA, one lane, narrow with concrete barriers on both sides for five miles at a time. Google still shows road work in I84, I'd be interested to see if it has improved as I have avoided it for the past two years, even if it meant I paid toll.
I've found a fairly enjoyable way to go south is to take I287 around to US202 then cutting over to I95 through Philly at some point. This avoids the NJ tolls and the Delaware bridge toll. Then taking Del1, cutting over to US301 just before the toll, then to US50 to DC avoids the other Delaware toll and the Maryland toll. the US50 bridge into Annapolis has a toll but only in the Northbound (they call it Eastbound) direction.
Google will show you the first part of this route but you have to fool it to make it show you the last part, by putting a stop on US50 near the bridge. Takes about an hour more than the toll route, but that's the same time as the I84-I81 route, is 25 miles shorter and also goes through some pretty country (yes, there is pretty country even in NJ). More turns, though, and Google will route you through a couple of narrow roads for relatively short distances, but no concrete barriers on both sides!
BTW I have an NYS Thruway EZ-Pass. With that you can pay the car rate, even with the biggest motorhome, on the Thruway. A huge help if driving on long sections of it. Needed to prove the the plate was a motorhome with the Newmar, but the MA camper registration was good enough for the Roadtrek. Just checked the Tappan Zee toll, it was class MHM, but only $4.75 which is the car rate, so the discount works there too!