If you want a down-to-earth quick bite at the Jasper Park Lodge, try the staff cafeteria, The Grizz. When we were there in early June, we got a pizza, had some beer and watch a hockey playoff game with some of the staffs there. You can find their location and menu on Google map.
As for room, we also had one of those rooms without A/C. Fortunately, when we were there Jasper cooled down at night very fast, and we could still sleep comfortably.