I've been on the Canadian many times and spent many a night in the single bedroom. There are two types of beds, the type that slides into the wall and the more common one which folds up into the wall (Murphy bed style). I find the sliding bed easier to move, although even the one that folds up is not that hard. If that's too onerous there are washrooms a few feet away, and the ones in the sleeping cars are rarely used anyway (coach is a different story).

The advice essentials are covered here. I'd reiterate this one: do NOT plan same day flights on arriving at your final destination. Sometimes the Canadian can be epically delayed. Best to leave a couple of days at the end for sightseeing or whatever and give yourself a good cushion of time. You may even want to consider a stopover along the way at a place like Jasper, Edmonton or Winnipeg. These places are interesting and they break up the trip a bit into smaller, more manageable chunks.