I know nothing of Hamilton or Quebec, so I'll stick to what I know.
Manitoba has the nominee program, although other provinces are expected to attempt to replicate it's success. Manitoba is also gaining ground on the inter-provincial migration. Success for Manitoba is success for Winnipeg, although of course not all of Manitoba's population growth is seen in Peg city.
Getting to our opinions, I'd love to see all cities hit the 7 digit mark in my lifetime. But to do the math that's about a 900,000 combined growth in Canada's population. Given the amount of time it will take these cities to reach 1 million, there's too many variables to determine who will reach the magic number first. To give an answer, of course Winnipeg will reach 1 million first