Thanks all - this thread indirectly answers the question I'm searching this afternoon -
I just cold crashed five gallons in the freezer of Katherine Kegerator (Big Kate to her friends), my 25 year old Kenmore frig / freezer. She can make a five gallon batch of 10% ale into a beersicle in 24 hours.
I usually try to intercept and keg up at about 16 hours or so, when ice is just forming. There was a beautiful dropout of yeast on the bottom of my cold crash bucket, and I was debating using it.
Now I know - make a starter and find out.
Again, thanks all