Many of the car rental companies are doing one-way rentals out of Florida at this time of year.
The rates aren't as low as they've been in years past, (I've done Hertz for $5/day, some cars have been $1/day) but still doable, esp if you're looking for a one-way car rental that fits their criteria.

From what i've seen, they're like $10-$20+/day (plus fees and gas of course).
They're posted on the web sites of the car companies, under "deals", or something similar.
I just checked Avis - looks like it's $10, with this AWD: S705900, and works for FL to PA.
http://www.avis.com/car-rental/deals...y-US_en-046266