I don't know the dog rescue situation in various parts of Canada, but I had an Airbnb guest a few years ago who comes down to the PV area on holiday almost every winter, and is connected with several rescue centers in the area. She brings dogs back to Portland, Ore. where she lives and the already arranged adoptive dog owners meet her at the airport.
When I said to her that surely there must be unwanted dogs that need adopting in Portland, she said no. That because people up north are responsible about getting their pets spayed and neutered, there is way more demand for rescue dogs than supply. People want a dog, but they don't want to buy from a breeder or pet store- they want to give a dog who really needs it a good home.
I certainly don't see any stray, sad looking dogs who need homes running around when I go to Canada in the summer.