I have been travelling the last six days—firstly across North Dakota and Montana along Highway 2 to Shelby, and then back east on the Trans-Canada.
On both routes, you travel at 118 km/h so you do make good time.
The travel distance to Calgary is very similar. The highways are very straight and the driving is easy.
Highway 2 runs about 60 km south of the U.S./Canada border.