Where do you get canned powdered milk?
I've seen it available from canned freeze dried food suppliers. Essential Resources is coming to mind, but I don't know if that is it. You can also get canned butter. Another option is also super pasteurized milk. This is safe non-refrigerated for quite a few months, possibly nearly a year. I saw some at the Meijer on the southside, but people don't know what it is, so it was near the expiration date already.