Sure, bring them in and keep them potted like a houseplant. I have a collection of different ee's and I bring most of them in. A few will go dormant, can't remember if black stem does. But don't panic if it does. If provided enough light, I don't think it will.

NancyAnn

You can also dig up the bulb and store it in sawdust in a cool dry envirement. Never done that myself I am in SW MO and they aren't suppose to be hardy here, but I just cover them with pine needles and straw and they come up again every year, and some are even on the north side of the house (they are under a big pine tree, and that might help to protect them) I like the idea of bringing them in in pots however, never thought to do that! think I will try that this year with a few of them, see how they do.
I am probuably playing russian roulette with them anyway, our winters seem to be continuing to get milder and milder, watch, we will have a bunch of single digit days some winter and I will be out there in the cold trying to dig up my Elephant Ears, cannas and glads!
micke