Should be hardy in your area. The big problem with this one is summer heat.
C. smithii is a synonym for C. calcicola, which may in time be found to be just a variety of C. tibeticum.
Thank you KyushuCalanthe. A woman once told me Cyp. flavum needs a longer growing season than where I live and she though the plant would be unable to "harden off" (is it the good expression?) before winter. What is you opinion?