Oh my, that photo really fascinates me. I got my first Phemeranthus last year. It did make it through our very cold winter (5°F) with no snow cover. Then we had months of rain. I thought I had lost it, but it came out of dormancy really late. It has very different leaves from yours, it's P. sediformia. No blooms this year, sure hope I get some next year.
I'll see if Rick has some extra seed. Maybe I have something I can send him seed from.
Would I be able to put the seed out in the raised bed this fall/winter, and let it come up on it's own?