Flying through the Atlantic Seaboard

I am considering taking a flight from central North Carolina to Cape
Cod in late March of this year. Up until all of my flying has been in
the Southeast, with IAD being as far north as I've ventured.

Playing with the AOPA planner the route looks pretty interesting -- go
just east of the DC ADIZ, then over Delaware and New Jersey (prolly
with a fuel stop in Millville or thereabouts) and then directly over
LGA, then arc (sort of) along the coast to Cape Cod. Can a C-172
actually get an IFR flight on a route like that (I'm thinking about
9000 feet), or should multiple reroutes be expected from ATC? Is
there a routing through that area that is preferred by controllers for
the small fry? Better or worse times to go through that area? I plan
to file IFR even if the weather is severe clear. For obvious reasons
I'd rather not take the overwater route to the east, but if I go west I
make the trip a lot longer.

(btw the actual route I'm looking at is: MOATS V155 MANGE V157 ENO
KMIV [prolly fuel stop here] RBV V123 LGA V475 PVD V167 PEAKE --
I know it can probably be cleaned up a little but that's the general
idea)

Any advice from veterans of this area would be appreciated!