Last summer I purchased a mandevilla vine to grow up my vine pole. I kept it in the large pot it was growing in and brought it in last fall. All the leaves fell off, which I understand is okay, and I kept it downstairs in a darker cool room. Not sure when to start it off again, I watered it in January. Now I have long shoots with almost no leaves. I mean like 3-4 ft. long shoots. Can I cut them back some more to get better growth for the spring? I put the pot by a sunny window now. (Another problem: this is a fancy low-E(2) window. Conflicting info on whether plants will get enough light to grow in my new sunroom.) Any advice for saving this expensive plant for this summer?