Interesting to see which languages cross the borders or are significantly distributed evenly on both sides, and which ones don't.
As you mention, the Chinese and Spanish speakers do not seem to be evenly split on both sides of the border (eg. the Spanish of Hispanic communities in states bordering Canada does not seem well connected at all to the Latino communities of the major Canadian cities, and Greater Toronto or Vancouver's Chinese community doesn't seem to spill into upstate New York or Seattle). I wonder if this is because post 1960s immigrants, and later waves of immigrant more broadly, were more likely to settle in big cities on either side of the border and so fewer would have settled in smaller towns in between. However, the German spoken in the Dakotas and Manitoba/Saskatchewan seem to be more continuous on both sides, and the French of Quebec/Acadia seems continuous with New England (I don't know if the French in the Mid-Atlantic or West Virgnia has any connection to it or to Cajun French at all; I know most other really old Francophone US communities are nearly gone, such as the nearly extinct Missouri French dialect).