Tilapia survival depends on a lot of factors. I am further south than most, large body of water and have a warm water well feeding it. Mine survive, which I like. Ones that do die are easily cleaned up by my dogs, turtles, coons, and birds.
I have put them in cattle water troughs to keep the algea out of them and they make it. I have had to pull some out of there every once in a while to keep numbers down.