I recently saw a tv show about the building of the hotel at Banff; it's spectacular, both the hotel and the surroundings. Can't you get there by train?
I live in a cold place so my idea of vacation is south. Not necessarily south of the border. I'd like to see Savannah and Charleston for sure. I don't know about Costa Rica, but Mexico has the worst diseases on the planet, according to my doc--worse than India and Africa he says. Argentina is so far south and so Europeanized that public health is not a problem.
you can take a train into Jasper, but I don't know about Banff...
if you go, you must drive from Banff up to Jasper......178 miles one way and very worth the trip because its constant scenery...
must see's are Lake Louise, and if you can, hike up to the farthest tea house....well worth it and excillerating...
also, Morraine Lake....