Uncrushed grains are good for months in a cool dry location, crushed grains less than one month. Freezing won't hurt. I keep all of my extra supplies in the top of the kegger.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk