your post has a familiar ring to it. I call it, sweeping it all under the rug......... or denial, or manipulation, or a combination of all three........
How do you do this for another month ? If it were me , I would simply be polite,
I could/would choose to NOT engage. Guess the time for talking has come and gone, it is now his turn, he can figure out his own life.
To ensure that my kids have a happy and peaceful Christmas, I would reach within and find my inner ignore button, if your mind is made up to leave, there really isn't anything left to talk about while you are still living under the same roof, ( division of property, marital assets, etc) all that can be decided when you are living apart, It's Probably a safer and healthier way for all involved, at this point less is more.
Hang in there. Keep the focus on you and the Kids.