I know it’s hard for you, but you really do seem to have the info you need.
My dog ignores their pair and usually just sleeps on the sofa or finds a fire to flop infront of. But she we will wanter into a room and complain he's on a sofa when so are hers!
Come now, OP, you know this isn’t reasonable of you. She has two lapdogs that she allows on her furniture in her house. She does not want your massive Great Dane on the furniture and has said as much. That’s fair; a dog his size can damage it just by clambering on and off of it. The answer to this is to keep your dog off of her furniture, not to point out that her little cat-sized things are also on her furniture. They could probably have a rugby match on a settee and barely displace the pillows.
Ditto you getting unpleasant when the dogs are brought up in a negative way. It sounds like she can’t just say “Oi, daughter! Keep that bloody horse off my sofas!” without causing an argument. So instead she is clumsily dealing with it by rescinding the invitation. Frankly I think the reason she said you can’t come is simply because she thought saying that you can’t bring your dog would cause a bigger issue due to your past hot-headedness/defensiveness over him. She likely was hoping that saying you won’t be able to come would make you volunteer to make other arrangements for your dog rather than her having to tell you that your dog isn’t welcome.
I think the previous suggestion of having your Dane spend Christmas with your in-laws or something is a great idea. After all, he doesn’t know it’s Christmas and won’t mind hanging out with other people in the slightest. I’ve actually never spent a Christmas with my current dog as it’s not practical to bring her. She goes to a friend’s place and has a blast without me. Friend always texts a picture of my dog wearing a Santa hat or draped in fairy lights or something. 😂
Since you plan on calling to apologize for your death comment, I’d drop in something about your dog going to the in-laws/your friend’s place/whatever you arrange and see where the conversation goes from there.
And don’t worry, you’re not the only one to be ejected from Christmas plans this year because of previous years. My offence was not dog-related but I am also not invited this year. 😂🤷🏼♀️