Same question - why isn't dad here asking questions?
I'm not trying to be smart at all - perhaps you need Al-Anon or something like that, to learn how we can't control people places and things. I have a couple friends who it has saved them from all the fraught of a custody battle.
Dad is not listening. If he were, he would get he has no legal rights at this time. He does not have the right to request child stay, he does not have the right to presume why mom is moving...it doesn't matter because with no legal rights she owes him zero.
And maybe he would write up an exparte over the weekend? Why the maybe? Is this a flippin emergency or not?
If it is, let him deal with it. He can request the courts grant him physical and legal parenting rights - he could do that the past 15 years. And perhaps he can try to get mom prevented, temporarily from moving.
But to give the daughter ideas she could move was crappy parenting...he needs to let that one go and even make amends to her. And I see red flags all over - this is affecting your relationship with the husband, best to not engage and take care of yourself.
The "maybe" on writing up the ex parte because that's him. He doesn't get around to doing things until he absolutely has to. He had no problem sitting and playing his video game all weekend, but if necessary he will come home tonight and write it up in a rush. And yes I see that as "how important really is this whole deal anyways if he's going to sit and play games all weekend rather than taking time to write up a declaration"? And if I ask him why he did that instead of focus on the declaration I'm sure I'd get "I am so drained by this process I just needed to chill out and not have to think about anything".