Your wife needs a few truth darts and some boundaries.
Those boys need her in their home town, demonstrating that she can be present and prioritising them and her marriage.
Wife needs put her Big Girl Panties on and Woman Up and you should be encouraging her to do so.
She has clearly expressed her desires for you to change. What do you and the boys need.
I am not sure why you are not using a children's therapist or social worker to negoitate her contact with the children.
Let them deliver her the news of what is in the children's best interest. If you don't feel able to deliever the boundary get someone into help. Let a therapist or social worker assist you to work through the barriers. Then see what she says and does.
To note I am not talking about marriage counselling. I am talking about an advocate for the children, whose primary interest and representation is for the children and there needs.
Sometimes Jim we need reinforcements. Your kids certainly do.
Your gorgeous boys have already been mightly f*** over by adults in their lives. What now we let them be exposed to a second round.
Jim I know you are trying to save your marriage with the woman you love, I get it. But man. This is hard to watch on your children's behalf.
Sorry Jim, not my ususal, carefully considered approach to offering supporr.