If you can get to Cranbrook, you can charge there and head to the supercharger at Invermere (134 km). From there you can just drive from one supercharger station to the next all the way to Vancouver (and back).
I always try to get enough charge to arrive at the next supercharger with at least 20% charge remaining. If I can’t, then I look for a supercharger station in-between (car navigation will skip stations if it thinks you can get away with it). Strong winds and AC/heating tends to eat up some of that buffer even though a recent update said that these things were now factored into the navigation.