Sorry about the fish kill.

Yes, several of the our northern members use winter aeration to keep ice off in a few places - which doubly helps with keeping the water oxygenated. Some even place one of the diffusers in a location to protect their docks.

Do you have AC electricity available relatively close to the water's edge? Solar generation, during winter at a northern latitude is a big ask.

See if you can find some of those past threads for winter aeration.

P.S. Having your aeration on during July and August will also make your fish happier during the lowest DO time of the year while not ice covered.

You may also need to add the rough dimensions of your pond in this thread. That will help the aeration experts give you some better specific recommendations.