I think there are likely many many confounding factors that would make extracting that data difficult. Separate from environmental/cultural factors we know that traditionally cold-weather cultures (Inuit for example) have genetic adaptions, including within the brown-fat cell pathways (for example: https://www.nature.com/articles/525429d). This would also make for confounders.

I think it's reasonable to go look for existing evidence, but it'd also be difficult to extrapolate.