Yahoo maps says what I figured, the traditional way up 64, 95, 270/70 and PA turnpike (something like 6hrs?): http://maps.yahoo.com/dd_result?ed=xTowJ...amp;tcountry=us
This would be fine if you pass the DC area before or after the afternoon rush (3pm-7pm).
If you are coming thru then, you might get creative and go out 64 to 81, then hook into 70 at Hagerstown, MD because rush hour up 270 ain't pretty.
There are lots of $50+/- motel rooms in Somerset, some of the mom and pop variety and though I'm not a regular up there, I would expect you could find one last minute when you arrive Friday night. There are chain motels too if you want to reserve a room over internet or phone.