tentseller makes some good points in his/her post

My suggestion would be Calgary to Jasper one day. Jasper to Kamloops via the yellowhead highway thus avoiding Field Golden area where the highway may be closed for the second day. Then Kamloops to Vancouver the third day All three days are just over 400 km each.There is a lot to see on all of these routes so you can insert and extra day in one of the locations which ever suite you best.