Well there's certainly a darn good chance of there being snow in Calgary in March..........there's also a good chance of encountering snow on your drive through the plains.
You should know that bringing a US vehicle into Canada on a permanent basis is a little more complicated than just driving through the border; the complexities depend on which vehicle you import.
You'll need to ensure and prove that the vehicle meets Canadian standards and you have to clear the export of the vehicle from the US with USCPB.
You can find all the information at
Registrar of Imported Vehicles - Importing a Vehicle
.