If you're not set on skiing, you could try Philly, NYC, or Colonial Williamsburg.

Deep Creek Lake in MD
Poconos in PA (lots of resorts, many with indoor water parks)

So after hemming and hawing for months, DH has finally agreed to a short trip over Presidents' Day weekend. However, most of the places I was interested in are booked solid by now. I'm looking for someplace within a 3-4 hour drive, kid-friendly (we have a 3-year-old), possibly with skiing (although DH doesn't ski, so ideal situation would be someplace with alternate activities as well - was looking at Massanutten but having a tough time finding a place to stay there in such short notice).

I really need to get out of town. Help please!