It could still be your belts slipping. Yes, believe me. If you check your timing and cannot read the timing mark because it seems to be dancing all over the place, it means that your harmonic balancer is separating and the outter piece that the belts ride on could be moved with the engine off. I've read on many occasions that this happens. It is a bit strange that the squeek you talk about only shows up at extreme cold temps, though. At any rate, check to see that your harmonic balancer is not separated and therefore needs replaced. Then, repost and let us know.