Don't want lots of BP in the house. Will BP store ok in ambient temp of -40 to +100?

As long as it stays dry and the can's don't sweat it should be fine. Might run into a bit of velocity variation due to the humidity of the powder.

The cooler and DRIER you can keep your Magazines, the closer you are to industry recommended standard.

Humidity simply is not a problem in my neck of the woods,...but temps in my mag regularly reach ambient levels, which are anything BUT cool.

GTC