I was wondering about that, the viability of keeping seeds for many years I presume? We've planted the leftover seeds from the year or two prior and just double plant, like instead of two or three kernels of corn, we'd put in five or six. Easy to prune back later.
Ours we just keep in the basement where it's cooler. I put a huge bag of perennial flower seeds I could only use half of last year in the freezer. Not sure if those will be any good this year, but we'll see!
Now for a seed hoarder, (kidding) I could understand wanting to get the perfect climate to keep them in, to keep them healthy. I am absolutely no help as you just heard what haphazard way I treat ours lol.