What I've done with my family in the past is have the person with highest status upgrade themselves and one more person, and then just switch BPs between everone between the gate and the plane. even on YEG-YOW-YUL same plane service, we used to switch the 2 sitting in J in YOW! Nobody ever cared.

The waitlist is another story...I never upgrade a full trip if i can't confirm the longest segment. I'd feel really stupid if i spent 6 credits on YUL-YOW in a CRA and got a free drin, and then spent 4 hours from YOW to YEG in Y

To be honest, they're short enough flights that it doesn't make a huge difference. If you have credits to spare, by all means go for it! If not, its not the end of the world.