I live in NJ also so I know the kind of winter you are talking about!
Have you considered buying a Rambo rainsheet and then buying a fleece or other
kind of warm liner so you have 2 functional blankets. The rainsheet sure comes
in handy when it's chilly and raining but not cold enough for a blanket, and
if you add the liner, you've got waterproof winter blanket. With the cold rain
and wet snows we get here, I use rainsheets more than winter blankets.-Amy