Not basically the same people. Canadian and US culture aren't the same. And the racial makeup is quite different.

57% of the USA is white, compared to 73% of Canada. Nearly 20% of the USA is hispanic, compared to 1% of Canada. There are many more Asians in Canada and much less people of African origin.

I don't reasonably consider that we can attribute black people and hispanic people simply existing to an additional 8% of GDP in healthcare consumption. That seems like a huge claim with no evidence provided.

I'd like to first see evidence that people of different race has a causality effect on healthcare consumption.

I'm not blaming races, I'm just saying the people are different. Even white Americans and Canadians are not the same.

Per the CDC:

Among men, the prevalence of obesity was over 8 percentage points lower in Canada than in the United States (24.3% compared with 32.6%) and among women, more than 12 percentage points lower (23.9% compared with 36.2%)

In the United States, the majority of the nonwhite population is black or Hispanic for whom the prevalence of obesity is higher than it is for the white population (3). Among nonwhite Canadians, the largest group is comprised of East/Southeast Asian persons for whom the prevalence of obesity is lower than it is for the white population

Canadians don't eat the same diet. The obesity rate is 36% in the USA but only 29% in Canada. I suspect that the difference in life expectancy is influenced more by obesity than by the healthcare system.

And yes we absolutely should control for climate, or at least for incidence of extreme heat waves. It's well known that heat waves kill a lot of frail elderly people.