What Is the Virtue Ethic of a Man With Multiple Wives?

If man has multiple wives and became a christian what he's supposed to do if polygamy is illegal where he lives. He should divorce all but one wife again, must not neglect providing for all of them and their children. I think the allowance in the old testament was a departure from the creational design and Jesus In the under the new covenant takes us back to the creational norm So rather than looking for is it commanded like a like as an thou shalt not we also need to look at just God's design as a whole Rather than is it sin not sin as our chapter verse.