Yeah, short notice, and really informal, but if people are looking to ride and haven't been there, then swing on by after about 2:30 or 3:00 until sunset.
Not hard to find - 1600 Pennsylvania Avenue - White House.
The 3 blocks in front of the White House have been closed down to traffic and were repaved. Pretty good surface for riding over in a section which had granite put down.
Gotta make the most of this weather!