I have several Star Jasmine plants which usually aren't completely happy after the winter (some brown leaves) but they bounce back but this year we had a very severe winter and they look awful, some of the entire plants are all brown leaves, some plants dropped their leaves completely.

Does anyone know if I should cut them back to try and revitalize them? If so, how much? 25%? What would be the best time to do so? Right away?

Thanks!