Here's my somewhat limited experiences:
In my area, folks rarely catch Redears outside of the spawning season. Most are fished while they are in shallow water, visible, on beds. That being said, I've also caught some by suspending a dark-colored microjig under an indicator.
Just in the past week, a friend of mine has been icefishing for them in the central Iowa area, and has said the ones he has been catching from 3 separate lakes seem to be suspending in the wintertime...NOT near the bottom. He hasn't caught ANY in the bottom 2 feet of the water column. And he was generally using ice lures (jigs or spoons) tipped with plastics.
Maybe something in this info will give you some ideas for your situation and location?
David Merical
St. Louis, MO