I went to a small middle school in Washington, DC in the mid 1980s that offered a bike field trip from Cumberland, MD to Georgetown, Washington, DC on the C & O Canal, 180 miles as I recall ... Everyone and their bikes (maybe 15-20 people) were loaded into vans, and driven from DC to Cumberland, MD.
Some highlights I still remember were:
- camping for the first time,
- the Paw Paw tunnel,
- Sharpsburg, MD and Antietam,
- escaping from the pack with a small group of friends and getting in big trouble! Park Rangers were called to find us.
I don't recall how many days it took us, maybe 3-4.
As I recall, there weren't too many places to eat or have your bike fixed along the way, so planning for food stops, provisions, tools and parts will be important.
I understand some of the lock houses have been available to rent for lodging along the way. I don't know how that's working these days.