Need Help with a very old climbing rose?

We have a climbing rose bush that is very old. When we bought the property it had a locust tree grown up next to it and the climbing rose went 15 feet to the top and even came down some. We carefully removed the tree and cut the excessively long leads. The stems of the bush coming out of the ground are about 2 in in diameter. It gets silver dollar size blooms of whitish pink all over it in the summer. We have wanted to move it but I was terrified so I took a lead and actually got about 10 different sections of it to root and grow. How far can I cut it back and will it harm it to move it? This thing is way out of control in an awkward place with nothing to grow on. Can I cut it down to the ground?