Appreciate all the help guys.
One more question:
Flying LHR > YVR this Saturday (12th).
I'm E50k on a Flex fare. Just tried to request an EUp to PE. Got immediately Waitlisted.
When I go onto AC's site and do what Monkai just described, it shows Latitude fares have space to EUP to PE but Flex don't?
What's the explanation behind this? Just trying to learn / wrap my head around the intricacies of how EUP availability / priority works etc...
Thanks.