As for powdered milk, my school  cafeteria manager gave me about 10 lbs of powedered milk... two years ago, I have taken what I need to use in BWCA, and the rest I keep sealed in air tight jars and it is still good.  I even use it around the house in making cornbread or pancakes or bannock or other things of that nature that putting milk in makes it better.  I can't remember the brand name of this milk, but it is good...  Mixed with water you can't tell much difference in it and skim milk as for taste.

Bruce