NE IFR
For many years I have done a lot of flying between Richmond VA and Allentown PA, so I know the "east of DC" portion of your route pretty well. You'll definitely get airways for most of that route, perhaps with occasional shortcuts. I've never had the least bit of problem with ATC in that area, quite the contrary, they seem to be uniformly awesome.
Obviously the freezing level and the clouds can get pretty low this time of year. Assuming 5000 will keep you out of it, I strongly suspect they can handle you there or lower between Norfolk and Philly.
I'm doing the good-weather dance for Thanksgiving because I really want to be up there flying as well.
One tip: you may want to go east of the Chesapeake Bay (V1 or V139) rather than west then over (V16 etc.). When crossing the Bay from the west on V16, Patuxent NAS (KNHK) is sort of a choke point given the DC airspace and the Patuxent Romeos. Annoyingly, that spot often seems to have its own weather system. Something about the interaction of that peninsula and the water can generate clouds even when it's CAVU elsewhere. So if you do go that way, pay particular attention to the TAF and METAR there.
I have less familiarity with the airspace north of Philly, although I've flown it on occasion. Last time I was up there (IFR from W96 to KPVC), I got queried when I was near Atlantic City about how many engines I had. I think they were trying to figure out whether they could send me out over the deep blue or not. I told them one engine and they sent me right over JFK. I've been sent over JFK on several occasions, and it's really cool. Something about flying "Victor One" gives me an Ernest Gann feel.
Have a chart/Foreflight/etc. ready when you're up there, because the controllers are not averse to giving you a major and rapid-fire clearance amendment "on the fly."
Good luck!
I usually have luck going V1 right over JFK at 7K headed north. 6K headed south.
Departing JFK Northbound, they usually have you go V16-V229. V16 should get you close to KGON.