Not sure that CX will be helpful on such AM ticket.
Your best hope is via FRA where CX seems to fly a once-weekly. They have an agreement with LH, but not sure that it would work with an AM ticket.

Of course, you know that current B countries could be classified as A with short notice.
The low number of cases in Italy is surprising with the summer holiday. Cases in Germany are increasing rapidly.

I assume that your wife will have spent 22 days in Italy and I would not try to cheat. I got a friend who did a washout in a B coluntry (not in Italy) with a British passport and was asked for proof of stay in a B country.