Joes have been relatively easy for me to get over the past several years--mostly because I have lived in either rural areas or smaller centres.
Its just basic math that the larger the population is around you, the larger the collector population is going to be too.
I advocate hitting those smaller centres when you can, travelling a bit further out-of-field to look for stuff.
Understand that smaller chains often carry this stuff, as well as collectible stores off the beaten path.
Look at retailers like Home Hardware, Canadian Tire, London Drugs, Fields, True-Value Hardware, Pharmasave, Winners and other similar local/regional chains. They can often have some Joe items on their pegs, and many have somewhat decent ( albeit small) toy sections. You would be surprised where collectible toys can be found these days.
Let's face it, EVERYBODY hits the big chains because in their work-a-day lives they are the easiest, most convenient retailers to look at.
With so many mouths at the same feeding trough there is always going to be less to go around, and finding stuff is going to be a matter of luck and timing.
You'll have more luck scoping out a Walmart in Winnipeg or Kamloops than you will at a Wally in Toronto or Calgary.
If you are serious about increasing your odds, expand your search parameters just a bit more, and try some of the out-of-the-way places when you can.