@Determined, it's what they call a "wicked" problem. Whatever you decide, there's consequences.
My sister and I did suffer aftereffects from Mum's unpredictable behaviour, but we respect Dad for his decision to stick by her. He's been an example of loving faithfulness. Funny thing is, as his memory got hazier, what stuck in his mind wasn't all the arguments over the years, it was his love for Mum and committment to care for her.
And we know that in many ways, growing up in an unsettled household shaped us, and probably not for the worse. Your kids will have issues to sort out as they grow up. When they get out and about in the world, they'll see how other families live, and it will hit home how far away from "normal" their family life was. (Likewise our own family... Older Daughter has made things harder and much more complicated for them than I ever imagined.) I'd encourage them to seek mentors of their own, maybe conselling as they get older, because sometimes their own family are too close to talk things through. And if they know you've got their back in doing so, it will help to reinforce that they can trust you as their father to support and to let go as appropriate.
S'funny... kids growing up is like a toddler learning to walk all over again. Letting them go, knowing there's a likelyhood that they'll fall over, and knowing when or if you should step in to help them up.
