Hi RainingButtons, glad to hear from you.
It is all rather traumatic really, for all concerned.
In thinking about the apartment, when one is so self-centered, I doubt it has crossed his mind that his apartment being a disaster means anything to anyone but him. He's good with it! In this case, with your Daughter's sensitivities and the fact that they do go over there periodically, I would actually broach the subject with him - as in, the kids won't be comfortable in your new place until you sort it out.
Alternately it could be a boundary which you share with him - the kids can't visit until the place is sorted out (this would be my personal choice).