I'm a big fan of those individual cheese mini-wheels they sell at Sam's club type stores. They come a dozen or so in a net bag. The wax keeps the cheese fresh even in the heat, and a few of the wax covers mashed in your hand, make a nice little fire starter for the evening campfire.  Snowdog is right, air is your enemy, so if you can re-package and maybe vacuum seal that will extend the shelf life of just about anything.