YAM-YUL. They can make it a milk run via YSB & YYB and schedule it on a Cessna Caravan for all I care. Just give me some way to get the heck out of here when Pearson is snowed in yet again, or when the last YYZ-bound flight of the day decides to go mechanical on us.
Other than that, YHZ/YYT to any of CGN, DUS, FRA, in that order of preference. Could be nominally within the range of the A220, but if we're asking for the moon anyway I'll send AC's 7M8s to the desert and get them to buy the A321LR for this route instead.
