First, take a look at where the freezing level is going to be:
Even if I could talk ATC into a routing over JFK and down the New Jersey coast, the northern part of the route would be a problem.
Now add in the moisture. Here's the forecast simulated radar image for the same time period:
Finally, let's look at a couple of Terminal Area Forecasts going out to 00Z tomorrow night:
KJFK 151737Z 1518/1624 05016G22KT 4SM -RA BKN015 OVC025
FM152000 05017G23KT 4SM -RA BR SCT009 OVC012
TEMPO 1521/1524 2SM RA BR OVC009
FM160000 04020G27KT 2SM -RA BR OVC008
TEMPO 1604/1608 4SM -RA BR OVC010
FM160800 02020G28KT 4SM -RA BR OVC012
FM161300 02017G25KT 4SM -RA BR OVC012
KBWI 151725Z 1518/1624 07012KT 2SM -RA BR BKN008 OVC012
FM151900 04012G20KT 4SM -RADZ BR SCT004 OVC008
FM152300 03013G23KT 5SM -RADZ BR FEW002 BKN004 OVC009
FM160400 02010G18KT 6SM -RA BR OVC003
FM161300 01010KT 5SM -DZ SCT003 OVC006
KIAD 151725Z 1518/1624 06007KT 3SM -RA BR SCT005 BKN009 OVC015
FM152100 03010KT 4SM -RADZ BR FEW002 BKN004 OVC009
FM160200 01007KT 5SM -DZ BR OVC002
FM161200 36006KT 4SM -DZ BR SCT002 OVC005
In the New York City area at the probable time of departure (say, 21Z), it's looking like gusty winds from the NNE with light rain and mist and a 1200 foot overcast. And for the ETA timeframe (about 23Z to 00Z) Baltimore is forecast to have 5 miles visibility in light drizzle with a 600 foot overcast and Dulles looks to have the same weather with a 500 foot overcast.
The only instrument approach into VKX, the RNAV 6, has a Minimum Descent Altitude of 680 feet MSL, so even if I could contrive to make the flight without icing up N631S, there is an excellent chance I'd have to go missed approach at VKX and wind up at Manassas.
I shall look at the weather again in the morning, but as of now it looks to add up to a nice train trip and a late (but safe) arrival at home.