I've got a clematis Montana, which is 6 years old. It had completely taken over one of my fences and blocked out the sunlight . It flowered last year( not a lot of flowers) and I decided to cut it down. As I'm disabled my neighbours very kindly cut it down for me, but left the trunk and branches of the clematis. At the moment it is completely bare, with no sign of any growth etc. Should it be cut right to the base ??? I'm frightened to do it in case it doesn't grow back at all. Any advice would be most appreciated, thank you.