Nice quiz, but every source I can find gives California a bigger population than Canada (39.5m to 37.5m on 2019 stats). My guess was about 40 to 36, so it's closer than I thought, but according to various sources I've looked up California has had a larger population that Canada for the last 35 years at least, and certainly has a current population greater than 37m.
https://citypopulation.de/en/netherlands/admin/
Netherlands (18.044K) now has 10K more people than North Rhine Westphalia (18.034K)
Canada https://citypopulation.de/en/canada/admin/ (41.288K) past California a while ago (39.431K) https://citypopulation.de/en/usa/admin/