I am sorry your DD, has left you feeling like this💐 , did you move to the area to be nearer them, perhaps helping out with babysitting, you must be feeling very rejected. I know she has left late to tell you but could not contact a friend from your former area and go and visit them.
If not you should tell her that you are disappointed you won't be seeing her and the GC over Easter holiday ,but you are not going to stay inside just to avoid everyone, if your Ex and his new wife can't be grown up enough to say hello if you should bump into them, which I am sure you won't go out of your way to do, then that is their problem not yours.