Ryan,

This might not be a whole lot of help, but a shortest path from Spring to DC is 1432 miles (60 miles/day), whereas going all the way to the coast before turning north gives you 1588 (66 miles/day). These both assume 24 days of riding (12/26 to 1/18), on interstates.

As others have said, you definitely can't be on interstates in the east, so I'd assume at least a 20-30% premium on top of the above. Given, a little slack for problems, I'd think 85 miles/day might be the right range, certainly no less than that.

I live 13 miles from the national mall on the NW side (Takoma Park, MD), and will be biking down for the inaugeration myself, assuming the weather is not terrible. PM if you guys need a place to crash for a day or two.

pete