There was a long thread about Calgary CG's on another RV forum recently. Several Canadians recommended staying as far away as Strathmore since the CG's closer to Calgary aren't all that great.
As for Stampede itself, I highly recommend being there for the opening day parade. If you like beautifully groomed horses it is quite a display. Parade route tickets are sold online and you'd better be buying them now. As for things to see at Stampede, in addition to the expensive top-tier entertainment, there are nightly rodeo and chuck wagon races which are fun for the family even if you don't know all that much about the sport. You watch the events in a huge stadium which even includes a glassed-in high-end restaurant. Tickets for these events are also sold online.