For East of Calagry. the Black Foot Crossing museum and nature trails is pretty neat. Especially in peak summer.
The Major Wille Medicine Wheel is also neat, but a little further off the TransCanada
the Brooks Aqueduct is also pretty neat.
Medicine Hat is also kind of an under rated city, if you wanted to spend a night or grab a bite after that run, and have energy for some sask stuff.
If you were not tied to the transcanada,
The Bleriot Ferry, to take the 838 through Drumheller, the Atlas coal mine, Wayne, Dorothy, then taking the 570 into sask is another scenic drive.
Or if you turned earlier you could visit the Dalum Lutheran Church Cemetery and head south to the trans canada.
In Sasks, i've always wanted to drive the ghost town trail.
https://en.wikipedia.org/wiki/Ghost_..._(Saskatchewan)