Statistics Canada's numbers will be the source upon which resolution will rest.

If the population of Canada is reported by Statistics Canada as being over 45 million at any point before 2028 (whether by their realtime population clock, in a quaterly population estimate, in census data, or elsewhere) then this question will resolve to YES.

Note that this question is based on when Statistics Canada reports Canada as having hit 45 milliion, not on when Canada hit 45 million, so even if Statistics Canada data/estimates/publications come out after 2028 has begun stating Canada hit 45 million before 2028, this will not count. The data/estimates/publications have to come out before 2028.

https://en.wikipedia.org/wiki/Statistics_Canada

https://www150.statcan.gc.ca/n1/pub/71-607-x/71-607-x2018005-eng.htm