What to do with a Praying Mantis Egg Case?

Hello, I've come across Praying Mantis egg cases over the years, in the Fall, and wonder how best to preserve them for Spring babies.
Where Momma put the case, on a leaf in my veggie garden, is not the best place for ensuring that the case will survive. I also found three cases on a wire ring that I pull from around my peonies, in the Fall. I hung the ring up in my shed, but I'd appreciate some advice on what conditions the egg cases need.
Has anyone else come across this? What do you do with them?

I posted a similar request last fall and didn't get any good answers. I put mine against the North side of the house near a window on the theory that a little heat loss from the house would keep them a zone warmer - just in case they weren't winter hardy. And I put them on the north side so they didn't warm up and hatch out too early.
I think it may have worked because I found a few little ones this spring. I had forgotten about the egg case until then, and when I looked for the egg case I couldn't find it. I moved the little ones to where I had seen little grasshopper nymphs. Never saw them again, grasshoppers disappeared too.
Anyway, my best guess was sheltered from weather extremes including sun.

thank you, pollengarden, for ALL of your replies. If I did not need an answer, I would not ask.

I try to place any egg cases I have to move in conditions similar to where I found them. In my yard there are usually two or three in a large miscanthus grass about 2 - 3 feet up a stem. When I cut stems back in spring just before new growth starts I stick the egg case stems in amongst the clipped off clump, The other place that mantises tend to hang out is near some rose bushes that get aphids early on. I suspect that this is a good source of food for new hatchlings. Both of these sites are in good sun until mature trees leaf out and warm up before most of my yard.

They don't have to be kept warm and they will need 4 -6 weeks or more to warm up and hatch. so they shouldn't be in a dark place where some sunlight won't reach them. There are a number of companies that sell egg cases to gardeners and schools and have instructions of how and where the cases should be placed, Check them out their recs.

I had a rare treat to be there when the 50-200 babies hatch out! In a half hour I stopped counting at 100 as they quickly dispersed around me raised bed garden. So tiny and they move quite fast. Good luck.

One time, when I was a teenager, I found an egg case, in Fall. Well. I did something REALLY STUPID. I brought it inside, for some unknown, teenage reason.
Some time later, I went away to camp. Came home, went to my bedroom, and that night, I was reading in bed. Saw the CUTEST micro-mantis crawl across the top edge of the book..

Then, WHAM! It hit me! When I dared to look around, there they all were, a literal TON of micro-mantises...all over my pretty canopy bed and much, much more...

Thank GOD for vacuum cleaners.
thanks, coleup, between you two in this thread, hopefully I will NOT repeat that Twilight-Zone experience.
My latest egg case was laid on a doggone turnip leaf, so you know understand why I asked the question. I LOVE those bugs.

:) gracye.. that sounds like something i would have done too..:) LOL
i too find cases in my roses.. also peony's .. i found 2 this fall.doing fall
clean up..so i too moved them to back shed..in a place where it'll stay dry..
i am grateful to them for there eating bugs off my plants every yr..