I'm up in NEOhio and know they'll survive the winter in 5 gal buckets. For small pots like that, why don't you just bury the whole pot and add a little mulch or compost or whatever you have for the winter. If you bring them indoors or even in a garage, you always run the risk of how much water to add to keep them from desiccating or possibly drowning them while leaving them buried outside, Ma Nature knows what they need. Or, actually just take them out of the pots and plant them in some temporary spots. Once spring comes you can dig them up and move to permanent locations, have done this many times.