I have overwintered it successfully (although I don't seem to ever get blooms! grrr)
Last year, I put mine in the bottom half of a clear plastic juice jug of potting soil. It seemed to like being in the filtered light of my kitchen window, and it didn't need very much watering. It mostly rested until about April, when the days got longer. Then, it put up more shoots quickly.
I didn't get to get it outside until about July. So I can't testify to the bloom situation (the plant is in the ground and healthy, but no sign of a flower bud).
I picked up another one, cheap, at Lowes (like I did this one last year). So I'll have two of them to baby through the winter (although they didn't need much attention at all).
Cooler indoor temps and less water with filtered light was pretty much my recipie.

Linda

Yes, I have in my solarium. They really, really want to be perennial in your zone, but they just aren't quite hardy enough. Although they need less water in winter, they won't go bone dry and last through it. You'll have to treat them like Linda does.

Sorry, I'm in zone 7-8a here in Memphis. Mine return in the ground and in pots but I have to say they don't bloom reliably. I do know the heat stops them for a while. They seem to like temps in the high 80's for blooms. I have had them for at least two years and I can say they seem to be all foliage most of the time. Bah! What's the secret to blooms more often?

Their blooming is highly light dependent. If you are feeding them, choose a formula with micronutrients and not too high in nitrogen. You can tell by the leaves when they need a boost.