As stated in a previous post, some may want to visit (or, in some cases, revisit) Fortress Louisbourg. It really should be experienced at least once. Others may choose otherwise and that leaves all of day three open to explore. Lots of places to visit although the much more exciting riding is on days four and five along the Cabot Trail.
Louisbourg to Baddeck is only about 1.5 hours of straight riding. There are a couple of alternate routes available for those who want to explore and then meet in historic Baddeck.
This is the formal route leading to Baddeck. You will note that a ride back to Little Narrows, by taking 223 to Grand Narrows and then meadering to the ferry again will bring you close to Baddeck as well.