[Thomas An.]

If you can post an example of prior work (or your current scene) it might help visualize what you are after.

Time-wise, the best way would be to treat this as a studion setup. No need to scale down your scene, keep it large and make the studio setup match the size of the scene. Use a large overhead emitter (to simulate ambient light) making the shadows softer and make the noise disappear faster.

Keep us posted