Julie

They're only ground hardy in zones 8-11 and then with a deep mulch. Again, they really don't like cold. I have heard of some people in the Eastern US leaving them in the ground, but I think that would be difficult.

I've also heard from another grower in the South that some varieties seem to be better at taking winters outdoors. According to her, the white or near white varieties are the least hardy. I'm not sure why that would be, probably because they are also the most expensive to replace.

Gin

Yes, I do have a couple of clivia. I like them a lot. I have the Clivia minata (the smaller orange one) and the citrinus (the yellow). Both I raised from seed. If I were to start collecting other houseplants, clivia would be right on top of the list.

You can store cannas in not-so-cold temps. I would still use the very dry peat and don't put them in covered containers. You might also want to try dusting them with sulphur before putting them away for the winter.