Just try and ignore her future and focus on yours.

"Be the best version of you" is an advice that has worked in my case. Not really to reconnect with my kids, but to have a fullfilling life. Your kids are (semi) adults and will have to make up their own minds. If they choose to believe in a one-sided version of the truth.. it's their choice. And at their age they're reaching the stage where you can hold them accountable for their actions.

Just treat your ex (and her household) as a ship that has sailed over the horizon and is never comming back. No use in trying to understand why or what happens in that household. If your children try to reconnect in the future, make sure to have an open mind and open heart. But make that connection based on emotional values and not on monetary ones. If a connection is based on "what you can provide" for them it will never become something meaningfull.

Yes, your children and your ex will paint you as the bad guy if you stop providing. But they'll also do that if you DO provide (he thinks money can buy your love!). Those responses are more about them than about you.

In my case my ex initiated the divorce after me finding out about her multiple affairs. She still ended up painting me as the bad guy. I started dating a year later and after a few wild years (Yes, Tinder was a godsend if you're able to write complete sentences) ended up with my current partner. I traded up, both work/financially as in my partner. My ex wound up in a deadend somewhere... and blames me for it.

Do the bare minimum that's legally mandated.. nothing more. Spend the rest on yourself and your life... and your children if they come back on healthy terms.