Sorry to see you hurting. (((Jo))) Deaths of loved ones can really stir up a lot of tough issues/themes, especially unresolved ones.
Don't you just love ILs? Parents often don't see their power to do ill to a child's M, and can create such trouble when they refuse to let go and let their children live their lives with their spouses. Yet, you ended up in a positive place with your FIL. That is a happy note. I'm sure you'll find your own ways to celebrate his life.
Andy's responses to your direct communication tell me he's not ready to be more than a horse's arse at the funeral. I'd stay away to, and plan to do something separate, perhaps at home, perhaps with your DDs or with all 6 of you at another time. But only if your needs aren't neglected in the meanwhile.
I keep hammering away at self-care on this BB to folks, and its b/c I'm convinced that the LBS is in starvation mode in terms of love/affection/meeting of one's needs after the bomb or S/D. If we don't meet our needs, who will? Its not surprising that when the next storm arrives or the next snub or challenging behavior from the WAS occurs, we crumble more easily then when we are stronger. It takes love and care to grow and stay strong, and at this time in our lives, no one can do that for us. Its all about us in that sense.
There is s/t about parenting well that can help heal past wounds that occured to us at the hands of our parents. And, my guess is, that healing can convey to the relationship between spouses or co-parents as well, if both people care deeply for their children.
Forgive yourself for snapping at the DDs, Jo. Let it go and just keep enjoying your time with them, letting yourself be vulnerable with them, and feed each other with the mutual love you share. That is a major event in all this for which to be thankful - you've had your 4 DDs more.