If you are considering DC during the rest of 2016, keep in mind that Metro will be single tracking quite a bit during that time. They are doing a major safety related overhaul and use of the system will be limited significantly for the rest of the year. Late night operations are being curtailed for this period.
Before choosing a hotel read the following: http://www.wmata.com/Images/Mrel/MF_Uploads/SafeTrack_Public.pdf
Choose a hotel close to your destinations and check the maintenance schedules so you can avoid the tie ups. Just to give you an idea, Orange line trips that typically take 30 to 40 minutes are currently taking 60 to 90 minutes.