Marriott or nearby Hyatt? Sheraton too. The Key Bridge Marriott is undergoing renovations but does have rooms available. I checked with the Hostelling International DC hostel but they are booked S-O-L-I-D. What about the YMCA?
UPDATE: YMCA said No. HI-DC said Yes but it'll be $29 each. One room at the Marriott will set us back about $35 each. Wes is checking with kin in DC for options.
UPDATE PART DEUX: Cancelled HI-DC. Got one room at Key Bridge Marriott. Bring a cable lock for the bikes.