You handled Monday perfectly. Yes, I agree, this time of year can be so magical not only for the kids, but for adults as well.
As for your wife, she's having some down days and the pity party has been playing in her head. To be perfectly honest, they go through period of crying, sulking, putting on that happy face and puffing up w/confidence. You never know who you are going to see when you come into a room.
Sounds like you are detaching a bit more and focusing on the children and you. That's wonderful! Keep it up!
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
