seo – Alternative Hreflang for multilingual sites with paging

So I am setting up hreflang tags on an e-commerce site. The sites are in the USA. USA, Canada, etc. The Canadian site will have fewer products than the US site, which means there will not be as many pages in each category as on the US site. What is the correct way to handle hreflang tags on these pages of additional categories?

To put it another way, the American site can have a category with 3 pages of products, while the Canadian equivalent only has 2 pages of products. What happens to this extra-American category page? Should I get an hreflang tag that links to the first page of the equivalent Canadian category? Shouldn't I get hreflang tags because it doesn't have a true Canadian counterpart?

Does it matter at all if you have a canonical label that points to the first page of the series?