@smiteri yes, both extremely hard to achieve! I think evacuation is a huge effort here. During the Blitz, the UK moved almost 4M civilians out of high-target areas.
https://en.wikipedia.org/wiki/Evacuations_of_civilians_in_Britain_during_World_War_II?wprov=sfla1
What percentage of Canadian civilians in the invasion zone -- about 25M people -- could move North or overseas is a big question. Obviously, we'd need military there, and workers in defense industries.