Wow, that's great you still get eggs through the winter!! That's odd about the production though. Seems pretty old to still not be laying!! Do you think it's partly breed?
Some of mine usually lay through winter, usually one of the Easter Eggers and then sometimes one or two others, but so far they haven't picked back up laying yet! I had the other EE start molting late August and then the rest started following slowly, into September and October. For a while I was still getting 1 egg a day but then since probably September or October I haven't gotten any and they haven't started back up yet. I am hoping they do. Some of them are finished with their molts.