Water in winter: Leave some room in your water bottles for the water to expand. They will be fine then. Pop cans explode because they are already under pressure at room temp.
Food in Summer: Mountain house pouches or similar. Crackers and other grains work well too. Heat will decrease storage life so rotate it through.
Food in Winter: Same as summer. Your Dinty will probably freeze solid and you'll have a Stew brick 
Ammo: Don't worry about this one. Modern ammo can withstand all conditions. If you are concerned, shoot it once a year.
That's a simple fix for the water, and one I figured would work. Thanks for the confirmation
Food: Grains are what I'm doing now. Over the summer I kept uncooked pasta in the car (which I enjoy eating raw anyways). For the Dinty Moore, you are probably right.

I'll still keep a few cans in there anyways, because I'll also have everything I need to make a fire.

Ammo: I planned on rotating it out once or twice a year anyways, so that works great.
If anyone can think of any other suggestions, I'm always open to more. No such thing as too much good info.
