A number of years ago, the Harrisburg Area Community College sponsored a bus trip to follow the route of Booth's escape.
After leaving from Gettysburg, we stopped in Washington to see Ford's Theater first, then proceeded to the Surratt Tavern. Unfortunately, it was a weekday, and traffic was frightful. We made it as far as Samuel Cox's home, but we had dinner reservations back in D. C. and the tour host realized that we would never get back in time for dinner if we proceeded all the way to the Garrett Farm, our intended final destination. So we turned around and headed back.
We never made it across the Potomac. However, we had Ed Bearss as our special tour guide. With him telling Civil War stories over the bus P. A. system, it was a very enjoyable day, even if we didn't go all the way to the end of Booth's route.
It appears that the tour advertised in the first post starts at the Surratt Tavern and will be going on a Saturday, so you won't have so far to go and maybe the traffic won't be so bad. Hope your tour guide is half as good as Ed Bearss.