This is an interesting question.
As for me, I'm planning Christmas the same as usual; whether or not H is a part of it remains to be seen. However, it has been occurring to me that maybe I need to plan completely different celebrations; in some ways maybe I'm a bit stuck with what we do. Now don't get me wrong -- I very much LIKE the way we have Christmas; I'll have the same people that we have had for years. Last year was the first time I did it by myself, no H involved at all; the previous year H was there, the year before that he asked me to cancel all other people and we had Christmas by ourselves, just H and me and the children. That was the first year he was away, and he was wondering......
I enjoy being hostess, this year I will likely host new year's eve as well. However, I take the point that it is stuff that H could 'easily slot into' if he chose to come.... stayed has pointed out to me that even if I have GAL, it still seems like I'm waiting. This isn't going to make me change my plans for this year, at least not right now, but it's a point worth pondering.
My children also very much like our Christmas, which is one big, big reason for doing it that way -- it gives them stability as well. However, maybe if I saved money we really could go away next year -- somewhere snowy and nice. That would underline a new life....
As to H; last year he didn't come because he went to see his mother in her care home; he may well decide to do so again this year, and have Christmas eve with his sister. I have no idea what he did for Christmas Eve last year -- in our culture it's almost the more important evening, as we do presents then, etc. He didn't come to church, after having told the children that he "might", but I guess he couldn't face it.
I don't know the status of the latest OW; she could be gone. It is likely that I will find out.....
Just points to ponder...