Don't know much about upgrades and am seeking expert advice here!
Currently rebooked from cancelled DL flight on DL. They can rebook me on a partner as it get's in earlier (cancelled flight was mechanical). Expertflyer is showing 4 seats in J. Flight would be Sunday night. The plan would be to use flying blue miles to upgrade the Air France full-fare Y ticket that DL would put me on. Is that how it works/does that make sense?
And what are the upgrade chances, roughly?