Zina with mother-in-law

In a moment of weakness, a man committed zina with his wife’s mother. He has repented and continues to repent. He no longer has contact with the mother-in law.

1) Does this break his marriage to his wife?

2) If so, is he allowed to marry her again in the future?

3) If the marriage is broken and the wife has no other place to go or cannot afford a place of her own, is she allowed to live in the same house but in a different room?

4) If the marriage is broken, does she need to sit for Iddat?