Sit tight until Spring. Assuming healthy plants in general, At some point on the stems or at a growing point, new vegetative buds will form and regrowth will occur. Once you see where the new growth is, you may need to prune any small stems and branches away that are not producing any growth from the point where they were eaten down to the new growth points. Consider feeding the plants as they flush out to help replace the energy lost to developing new buds.