Your kids are old enough now to have their own individual relationship with him or not if they choose to.
If he is trying to "triangulate" them into your relationship dynamic,
perhaps you should tell the kids to make their own Xmas arrangement with him should they want to and that he is not welcome in your home at any time.
Go full on No Contact and mean it. Give yourself at least a good six months "off" from dealing with him in any way, shape, or form either directly or indirectly.
Make sure he gets a calender of any school-related events for your kids, and do not interact with him about it.
He can choose to participate or not, but as as grown up he can figure it out himself.
I would also consider proceeding with the divorce and have contact with him only through lawyers in the future.
He hasn't earned the right to all of the real estate he still has in your head. Time to evict his drunken arse.
Use the anger, which I agree along with dandylion is healthy.
This limbo you've been living in of separate-but-married so he can drink and still have a possible landing pad really needs to stop.
For whatever reason, intentional or just selfish drunkeness, he continues to use and manipulate your vulnerable emotions.
Time to put a final stop to that and put Butterfly front and center.
This is no way to keep living and you do deserve more.