I know that I am in a warmer zone than both Jeanie and Debbie, but I have had great luck with the end of season sales and healing the whole pot into the back of my garden. I dig a large hole and bury the whole thing. This way, the plant does not have to re-establish itself until Spring.
I like to get the discounts that are offered at the end of the season. I have done this with many different types of plants, including heuchera, and have only lost 1 plant in all of the years that I have been following this practice.
