I agree, many are very hardy. We grow some species in our garden (USDA zone 3) like europeaum, canadense and caudatum.
Unfortunatly, the flowers hide under the leaves, but since they are pretty large for the genus, they are more easy to admire! About the cold rest : Ling Ling was outdoors until frost. Green Panda is grown indoor for many years and did not seem to require a true cold rest to bloom.
First I've been introduced to this species. Panda faced ginger, great, just another addiction I need. Yep, that is a beauty and I want one...................ikes...............