Wow.
I adored my late MIL and made a mammoth effort to maintain that relationship after her son and I split up. We lived 5 minutes away at the other end of the village (and half an hour from my mother), saw each mother once every week or so. There was no whining, clinging, pushing for 'more, more, more' from either mother. Sometimes we went to them for Sunday lunch, there is NO way any of us would have considered holidays together. We attended 'big' birthday celebrations at MIL's house, with her many friends and my ex-DH's aunts, uncles, cousins and step-siblings, all jolly good fun - but for the afternoon and evening, not staying there for a week! MIL had had her time parenting her own children as she wished, she didn't tell us how we should parent ours, neither did my mother.
On the odd occasion that MIL babysat she did NOT drink. AT ALL. Perhaps that's why she didn't babysit a lot ( ! ), but had she opened a bottle of wine (or more) it would have been the last time she looked after them. That's disgraceful on your part, shame on you.
Children should wake in their own house on Christmas morning, not your house, unless they have always had a tradition of going to a grandparent's house for a few days. That could be the case if the grandparents lived many hours away, not as close as you are. And kids shouldn't have to spend Christmas Day in the car for hours either. Can't they see you and the other grandparents Christmas Eve or Boxing Day? Your kids did, surely, or did you always go away for Christmas with them? What does your son remember about Christmas with you when he was little? Maybe his wife had happier times and they're trying to replicate that? Whatever, they're grown up and their decisions for their family aren't yours to criticise, whine or grumble about.
OP did you have to do everything your in-laws expected when your children were growing up? I can't imagine why you would expect to interfere so much, unless you had to tolerate it yourself. What is your son's memory of the part your in-laws played in his life?
Let them be. You sound a real nightmare MIL and honestly I'm surprised you are able to see your grandchildren as much as you do. I don't think you can grasp that this is all about YOU. Why do you think they can't build a rich tapestry of happy memories that aren't centred around you?