I think your trout will feed now if you toss some pellets in the open water area. I think Cecil Baird1 feeds his trout in winter by adding food to the open water area of the diffuser. Cecil will probably respond to this thread.
Why thank you and thank you to the OP for a topic that's top of mind right now. My trout would hardly feed at all when the ice was coming on this winter so I simply quit. I'll give it a try tomorrow.