I'm familiar with the QEW - I-90 - I-79 - I-70 - I-270 route. It worked for me. And with the current forecast, the roads should be clear - not even black ice to worry about.
From Buffalo, that will be two hours to Erie, two hours to Pittsburgh, two and half/three to Frederick, and I forget what it was to D.C. - so ten hours, give or take. A couple of the rest stops in Pennsylvania have pretty good scenery, especially those down in the mountains south of Pittsburgh.
Of course, having said that, when some of my co-workers drove down to Frederick for training, they took the I-81 route.