Dh works for the ARC. They follow all of the Government Holidays and I am pretty sure everything is open. The nice thing is, we generally get snow in Jan and Feb so you are picking a good time weather wise...cold, but tha tis all. Plus, there are a lot of extra things to do, like you get to see the Christmas Trees from all the states and the national christmas tree all lit up at night.
There are usually concerts going on there too. And while hotel and Metro are expensive, everything else is already paid for through tax dollars...so free once you get there. I think if you dont mind the cold..it is a great time to come!