I can only tell you what I do in the Baltimore Washington area. Dulles Airport hotels are VERY well priced on the weekends. $50-$70 night for some great properties and great locations. Even a RC at Tysons for $149 if I want to treat my DW to something a little nicer.

I would look for areas that service business travelers primarily. They drop on weekends. Resorts in low season. Etc. Good luck.