Feeding as many as you do, I would be uncomfortable with that amount of back stock too. I worry all the time that my gorcery store will stop carrying the Coleman's breasts and thighs that I get for Mazy cat (certified organic non GMO verified project) OR the whole roasters, which is how I get her liver.
Unfortunately I can't stock up on it, much, because I have no where to put it. I have two pounds each of the breast and thighs in my friend's freezer, but I have to take a chance that there will be a roaster available next time I am getting low on liver for her.