Don't forget Louis St. Laurent II, grandson of Prime Minister Louis St. Laurent. Currently serves as an Attorney in Florida, but still has deep roots in both Quebec and the Liberal Party. A few changes to OTL and who knows, he could conceivably be a prominent cabinet minister or such in a possible TL. Move over Trudeau's, and make way for the St. Laurent's.
Hell, he's got the making to be a Florida politician. He ran for the state house as a Republican in 1966 and worked on various campaigns after that.