I would not trim it yet.............can you put 4 stakes around it and put heavy clear plastic on the top and sides...........put several pin holes in it for it to breathe.............in early spring when it starts to warm up take off the cover and see if it is showing new leaves at the bottom..........then you can trim it off the top. Next year...danger of frost of ice.....do the same thing to protect them. Good luck with your plant.