I am going to have to jump in and say that the Meow Foundation is an organization that does what they can, with the resources that they have. I am involved and keep up to date with Calgary's animal rescue non profit community, and things can be tough.
I also want to point out that being a no-kill shelter, the Meow Foundation does not just take in every cat. They take in only stray and abandoned cats and emergency cases. They foster out orphaned kittens/pregnant cats to homes that can accommodate to this. They do not house feral cats since this is very stressful for the cats; instead they run the Trap/Neuter/Release program in order to implement population control. They base their intake on capacity. If they have no room, they cannot take in more cats. Given that they are a registered charity and humane society, I highly doubt they would "unethically" overload themselves.
Also, in Calgary for strays that do not end up somewhere like MEOW, cats often end up at the Calgary Humane. While the Humane Society is an awesome organization with an open door policy, they do unfortunately have to euthanize in the case that an animal is too unhealthy to treat, un-adoptable, or has extreme behavioral issues. So... would you rather see a stray cat in a crowded shelter doing the best they can, or a shelter with an open door policy also doing the best they can, but may unfortunately have to euthanize the kitty if is isn't adoptable? It is a tough choice because obviously neither is ideal in a perfect world, but it is reality for most animal rescues.
I also support the work the MEOW foundation does within the community to reduce the stray cat population. Not only do they have the TNR program, but also SNAP- Spay and neuter assistance program. Scope it out.
I advise that we support organizations like MEOW in order to create the healthiest environment possible for the animals, and realize that in a large way, it is society's fault that these poor kitties are in a shelter in the first place. Spay, neuter, and license your pets! Don't take an animal into your family and then abandon it. Adopt a rescue! read more