Surges in population do not occur near the Canadian border
The United States has a population of 328.2 million people as of 2019. California has 39,747,267 residents, Texas has 29,087,07 residents, New York has 19,491,339 residents, and Florida has 21,646,155 residents. Those figures are just provided to put this population spike map into context.
As you can see, the surges are biggest in states where the population is already among the highest in the country, with little to no spike close to the Canadian border.