I have them both in water and the ground. Watch the runners, I cut them as soon as they get a leaf and either transplant them or sell them as shoots. They seem to be in demand here.
I don't know how they winter over, our winters are not as severe. I have one now that I have to decide about splitting. It has started to burst the plastic pond pot it is in.
You might consider putting half in a pot that can be brought inside for the winter.