If time permits and the glacier highway is open, take your rental from Banff / Lake Louise and take the Glacier Highway: Alberta Highway 93:
https://en.wikipedia.org/wiki/Alberta_Highway_93
It's an epic 2.5 - 3 hour drive up to Jasper and a full day with a few stops along the way. Compare it to the Great St. Bernard Pass in CH but longer and incredibly beautiful. Strongly suggest it!
As much as I love Calgary, the city itself can be seen fully in a day or two.