Ice out spring channel fishing can be very good on the Mississippi. I haven’t been out this year as in the past but here’s some indicators that might help you.
Shad. They die with changes in water temps and get frozen in ice. Any place there might be a concentration of dead shad should be a smorgasbord for channels.
A little more specific, tribs that have frozen over will contain shad in the ice. As it melts it frees up the shad and they drift down stream until they come to a (deeper) hole where they come to rest. That location is your 1A location.
Since there isn’t any good/easy/legal way to get shad for bait right now, I would use smaller then normal slices of sucker or even fathead on my circle hook. I’ve used Sudden Impact fiber bait with good luck as well. Just bend the barbs down on a treble hook and push it into the fiber bait. The fibers will cling to the trebles and will stay one and give off a good scent for a long while.
Hope that helps, Good Luck!