do i cut to ground level in the fall
I would leave an inch of stem and the basal rosette of leaves. This helps you find it and if the winter is mild, it may live through. Some professionals are beginning to recommend cutting things down in early spring before growth begins. The plant "self-mulches" this way so there is less heaving of plant crowns during freezing and thawing temps. If the plant has suffered disease or pest problems during the growing season, remove all plant parts before winter.