Try the Transform Shader. It has translate and scale options. They apply to any shader that is connected to its "shader" input. The main input is not affected by these options, allowing you to merge a translated/scaled branch of shaders into the rest of your scene.
It may not work in all situations. It works by modifying the texture coordinates before calling the shaders. Any shaders that use these coordinates to drive their internal functions should respond to the Transform Shader, but not all do. Any shaders you are using to control placement of certain shaders may be affected in undesirable ways.
The magnitude of displacement is not changed, so you may still need to edit displacement amplitudes manually. For future versions it may be possible to add an option to do this automatically, but it's not likely to give 100% predictable results.
Matt
