Yes we we're surprised to bring this plant through a winter! It's best planted out in the ground or kept in a pot in a cold glasshouse. If the root freezes it will die but it'll be okay in the ground. Largeish sage-green leaves make an impressive clump from which grow the flowers from the stem terminals. These are bright yellow shaped like lobster-claws! It runs beneath the soil surface but is not invasive.
We believe this form has been given the name 'Ice Storm' as it does have a silvery overlay to the leaf.