I am double degreed, I have a psych major as well as a chemistry major. Also, I am a mental health professional and an MD. Your wife is projecting like whoa! Small children can say they want to live here or there but the fact of the matter is, they need to be with the most stable parent. For her to say that the only solution is to uproot your son and move him to Canada, away from you and his siblings, is preposterous.
You did the right thing by informing her of your sons' situation, you also did the right thing by not responding to her "opinion" of what will fix the problem. Keep doing what works.
M 10yrs T 13yrs BD #1Oct 2015-PA between WAH and COW BD #2 April 2016-WH resumed PA, she broke it off Jan 2 2017 WH says he wants divorce April '17-Letting go 2018 D busted DD8, DS6, DS3