Well, the Park Board did not include this beauty in their https://vancouver.ca/files/cov/ted-and-mary-greig-garden-50-rhododendrons-of-interest.pdf document - at least it doesn't seem to match any of the descriptions. The only one I can't rule out from the descriptions is R. x 'Jean Marie de Montague', but the petal edges are not frilly enough. I'm not sure I remember exactly where I saw it - it might be off a path or two north of the Grieg Rhododendron Garden in Stanley Park. I don't really expect to get a name for this. That's fine.