Pat's got the right of it. Fill with glue, unbrace, wrap with carpet thread. Wrap the same locale on the other limb just because. Don't waste a skin on backing. If you want to back, use silk ribbon or even heavy brown paper bag to keep down the mass of the bow.
At this stage, reducing the draw weight isn't going to help any; I'd leave it alone.
Humidity or lack of it isn't going to help or hinder the situation. I wouldn't necessarily switch bows, but since you've got more than one, take this one and a backup.