I think you are in the wrong forum but since I have some, I will tell you what little I know. Officially, most (?) if not all will hit a hardiness wall around Zone 7. But there are some people who claim to grow them in well draining soil that they winter protect. I am not sure if their methods can be duplicated but see the post in the link below. You may want to contact some of the folks via GW Mail for details.

Here is a link that might be useful: Elephant Ears Post