Here's what I've been doing. Keeping opened #10 Cans of Mountain House dinners for 3-4 months. Seems OK taste-wise. Will this kill me?
I open a can, take what's needed immediately. The remainder gets divided into two one-quart wide-mouth Mason jars. I throw the little packet into one of them (that one I use first of the two, from this point), pump the air out with a Food Saver and store the jars in the freezer. After next use I pump the air out again and back into the freezer. When the first jar is gone the packet goes into the other jar. Recently I bought some de-oxygen and de-humidity packets and I've been throwing an extra in the jars.
The life of an opened #10 can in terms of just putting on on the plastic cap and storing at room temperature is usually described in terms of days or maybe two weeks.
I tend to eat small meals, and I also add my own dehydrated beef/shrimp, spices and other ingredients, so I get a _lot_ of meals out of a #10 can.
I also store bulk freeze-dried chicken and my own home-dehydrated cooked shrimp and cooked ground beef in the same manner, though I am very cautious about the shrimp and try to use it up in a few weeks.
Thanks for sharing any knowledge on the safety of this.