On my one and only hive I have two supers that are ready to extract and a third one that is about 60% full. Should I extract the two full ones and leave the third or do all three? I'm wondering about overwintering here in central IA.
Matt, I would extract the two capped supers and let them finish the last one. I don't know what your local conditions are, but I'm far north of you and my girls are still bringing in honey. Uncapped honey has a higher water content.
I'd leave the 3rd super because it has a high proportion of nectar (uncapped cells) to honey the more uncapped cells the higher the water content and the higher the water content the more likely the honey is to ferment but if you're into mead extract away.