I have 2 mandevillas that I bought last summer. I am in Northern Michigan near Lake Michigan. One of the mandevillas is in a window and growing beautifully, though not flowering. That is okay. I am waiting for summer to put it outside again. The other is in my kitchen and I have a cat like likes to climb its trellis. This unfortunate plant had a few live leaves on it. Now they are all dead. Is this plant most likely dead or dormant? I am not watering it anymore.