Hi

I use skyscanner and google flights. Kayak doesn't show all airlines.

Note: I'm not sure if you're canadian, but the airlines started increasing upgrade category $. It was ~$100 to upgrade to refundable seat + seat selection + checked suitcase (ie econo flex)... it now varies per destination and can be closer to $143 -$237!!! (or other hard math marketing $, ie non rounded #). There are still options for the $120ish upgrade if you look.

Also WJ will soon be reinventing their loyalty program.

Safe travels.