[Subversive_plot]

I've noticed that some seeds seem to survive freezing temperatures and go on to sprout and produce plants when the weather warms.

Orchid growers know that even tropical orchid seeds can be frozen and thawed to grow at a later date if you are careful.

I'm going to try a little experiment over the winter with some tomato seeds of a variety I don't intend to grow again. I will place in a jar with desiccant for a week.  I'll dry the desiccant after that (oven), cool that down, place the seed back in the jar with the desiccant, pop in the freezer. I'll leave it in the freezer until spring. This is the same treatment that orchid seeds would get.  I will check germination. After a thaw in the refrigerator.  I might try a few other seeds too.

I'm thinking this might be a good way to extend the shelf life of fresh seed that you don't need many of each year.

[mumofstig]

I don't know if you have the same thing in USA (I'd presume so) but we have several seed banks, that freeze seeds, to ensure Heritage seed varieties aren't lost forever.
Last year, or maybe the year before  the polybag of saved seeds of Mennonite Purple Stripe beans, was alive with pea and bean weevils by Spring. I took a chance and put it in the freezer for a week or 2
When the bag was defrosted the bean seeds were still alive but the weevils weren't 

[Snow]

Would be good to test it on seeds that don't keep well, like parsnip, carrot and alliums. Tomato seeds keep well for over a decade normally!