In your zone, as long as the temps stay above 32 degrees, they'll be fine and need no heater. I'd pot them into one gallon pots if they aren't already. Leave them out or place in the greenhouse, your choice.

I have to agree, no need to keep them in a heated greenhouse. I pot my bands into 1gal pots and keep them in a cold frame over the winter. I did it last winter and it really helped especially when the temps went below freezing with rain and wind.

My greenhouse is not heated unless temps get really bad - for us, that is in the 20's. I have a small heater, it just takes the chill off. Due to humidity, we get bone chilling cold even tho temps arent like, say, Minnesota. I was mainly worried about winds, and really cold rain. I just thought they wouldnt have a chance to put any root growth on, climitize themselves before winter hit. I just got a little group in from Vintage the other day - since my greenhouse is actually more like a big coldframe, I think I will pot them up and leave them out until we really start to get cold weather - which we are not, momentarily. They are growing well outside now.....so maybe I will just bring them inside when winds start to get bad, and weather is much colder. I didnt want to take a chance on getting them mildewed or putting them in a position where they werent going dormant.
Judith