In this rural county, daily new infections are at something like 400/million. That rate is arrived at with a big enough multiplier, but it is a reasonable basis for comparison. Our cumulative case / million is ~23000.
* https://ourworldindata.org/grapher/covid-19-death-rate-vs-po...
See also:
> We also find that after controlling for metropolitan population, county density is not significantly related to the infection rate, possibly due to more adherence to social distancing guidelines. However, counties with higher densities have significantly lower virus-related mortality rates than do counties with lower densities, possibly due to superior health care systems.
* https://www.tandfonline.com/doi/full/10.1080/01944363.2020.1...
On that scatterplot you linked, Canada is way down there in terms of population density. Yet the vast majority of Canada’s land area is uninhabited wilderness to the north. Most Canadians live within a narrow band of cities running parallel to the U.S. border. In addition, a significant minority live in many scattered rural areas outside of that band.
So the question is: how do you measure Canada’s true population density? Do you only look at the high density band? Or do you include the rural areas? Where do you draw the line between rural and wilderness? There’s no easy answer.
Look at past pandemics for reference, everybody was hit. The Spanish Flu spread in isolated arctic populations just as well as NYC.