I know you must have had a lot of documentation to get an order this strict. I'm not saying she's not an alcoholic but is she a danger to the kids? Does she put them in her car and drive them around? Does she cuss and tell sex jokes or other things? What is it that she does when she's drunk? Is she a danger to them?
And why do you have so much control over dad's visitation? Is he a danger to them too?
It's very obvious you hate them, and him, and feel the power of total control. It comes across in your post.
Why do we think you hate them? You stated:
"I barely saw my kids all last week".
That's what happens when kids go see their dad for visitation. Most kids go for weeks and months at a time. Other parents deal with this all the time.
"I did not consent to so much time away from them".
They're visiting their dad, it's not about you. You have them all the time, it's dad's turn.
"I confronted my ex".
It didn't concern you. His parents can come any time they want. It wasn't his time to see the kids and his parents can see him when ever they want...but when they asked, you allowed the kids to go over. So it must not be so horrible over there. You're also "allowing" them to go away to with him and his parents for a week, 2 hours away, so again, they must not be this bad. So this reinforces that it's all about them and you and not them and the kids.
"She has always been mean to me".
So? Is she mean to the kids? Is she constantly punishing them or talking down to them? Again, the visits with them are not about you.
"extremely difficult to be around for anyone not related to her by blood".
Are your kids adopted? Then they ARE her blood so according to you she's nice to them but not you. How does she treat them? If they're mean to them because they're yours then the mediator needs to make sure you both get to address that issue.
These statements are why I wonder if this is more about how you feel about them or if there is a real danger from her drinking.
I get it, you hate them, I don't blame you. You want to control their visits because you don't want the kids around them. I get it. But, the kids are going to get older and see for themselves how you are treated and how you treat dad. If they only see your actions to control and limit things with dad who do you think they'll want to be around more? Dad's already have it easy because they get the kids and go do fun stuff with them. Mom has to work and struggle to make ends meet and can't afford to do all the fun things.
In all honestly is sounds like you guys need a court ordered mediator. Someone completely that in no way has any interest in the outcome of the sessions.
I say this so that both of you have your say without the other one being able to interrupt or butt in or change the subject when one of the people are getting things off their chests.
This will help you and him resolve your issues that are effecting your children.
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The point of all this is that if your ex's mom is truly a rip roaring alcoholic you and he need to do mediation so he can hear you and you can hear him and the mediator will help you guys come to an agreement where you can let him have his visitation and he can manage his mother.
You guys can come to much more agreeable terms of visitation. With everything written down. He needs specific visitation too. If his parents come in town he can cancel or discuss it with you. You can say no to that BUT he needs specific time with his kids that he can count on. That you can't say no to if you don't feel like it.
When it's this stressful for ex's to agree on things it's better to have a mediator help you write up a better court order. With reasonable restrictions regarding all alcohol use and smoking and everything that the kids could be exposed to at his house. This way all your kids have to do is call you and say "Hi mom, grandma's drinking again. I want to come home."