Looks like you did fine, nothing wrong with it. I do want to comment on a different perspective because I think you get quite a bit of advice to completely avoid the holidays with her as you don't owe anything, that it could cause mixed signals, etc.
Personally I think people get too strict on not spending time together and miss it's intention. Balance, balance, balance. The point of not spending holidays together and let them cake eat is to stop them from keeping the benefit of the M without its commitment. Yes, it's always important to do things in a way that's not punishing or rude/cold. It's also important to let them live their life and experience the consequences of their actions also. What I don't agree with is cutting off all that contact which could help your cause(depending on how it's initiated). To protect yourself emotionally, send mixed signals to the kids, whatever reason it may be.
Balance it out for a while, maybe do one together and the rest apart, don't just cut it off completely because it's easier to not interact with her. These are still opperunities to show her the life she's missing out on and the man only a fool would leave. Dangle that carrot don't just remove it.
I know this part is going to mindfuck you and maybe its not the right time but ill just say what I'm thinking right now. I'm sure others are going to heavily disagree also. As for you and being hurt, you can get over the dissapointment in time. Db'ing is about doing what works to improve ourselves and ultimately save our M so don't make a decision because it will make you feel better or avoid pain short term. Isn't that exactly what we avoid at BD, something like moving on to a new R because it will make us feel good. I see acting a certain way for the sole purpose of removing the pain the same. Sure, there is always a time and place and for most of the time it might make sense not to do holidays because of how the WAS is acting. Just understand that might not always be that way. Basically if it's painful but might move you toward your goal then don't do it to avoid that pain.
As for the kids, saving the M in the long run I think is more important than some mixed signals now. They are resilient and will be ok, much more so if you save the M.
Please don't see this as a means to pursue or jump up those expectations/fears. At times in this process we do things that don't make sense and are painful and I more just want to avoid the misconceptions of why we say certain things.
Accept what is, let go of what was, and have faith in what will be
