proofing after refrigeration

After a year of baking bread I am happy with how much I've learned,mostly from the Freshloaf. I bake almost  soley with sourdough. My problem is consistantcy in proofing. I almost always do an overnight retard and what happens in the retard varies from half rise to more then doubled. So the Q. is when to start shaping ,rest, So far it seems the bread wants to say now. Finger poke test sometimes says its ready out of frig.  Any help appreciated.  Patrick from modesto