Well.... on these cold mornings when I put it in D, it slips until the engine temp warms up, maybe 5 min. Then no problem at all. I drained the transmission fluid and replaced twice. Each refill I have had better response on cold mornings, almost to the no slipping point. It is also shifting better. I am going to drain and replace the transmission fluid another time. I am trying to flush out all the old fluid from the converter. It has been a very long time since the fluid has been changed.

When the outside temp warms up, the problem goes away completely.