Just a few things I would say to be aware of. VIA Rail schedules are at the mercy of CN freight trains and as such get bumped quite a bit. An on-time schedule is a hard thing to find. Best bet is to browse tripadvisor's site for VIA "The Canadian"
Sometimes the Rockies sections are run at night. VIA runs on CN lines as CN used to be a government railroad corporation, like VIA. CP has no passenger service.
Going East after the prairies means taking the Canadian National line through northern Ontario, not the more scenic Canadian Pacific route around the Lake Superior north shore. Be prepared for endless swamps, lakes, rocks and trees, after the endless prairies.
Train nuts will be fine