All the new growth will freeze if the temps get cold enough. Be patient and wait until the end of April to prune.

Won't the plant already be pushing out new growth by that time? I don't want to have a flush of new growth and then cut it back to the ground, right? I can't remember when the vine does flush out, but end of April sounds a little late. I have a lot of plants growing in the garden by then. I would agree that now is probably too soon. We will have freezing temps still to get through. So, I take it that as soon as I prune it, it will stimulate the vine to push out new growth during a warm enough spell and then a subsequent cold spell would freeze all the new growth?