I have no idea who ever though that mixing orange juice with champagne would be a good idea, but I speculate it was a medieval all inclusive cruise line trying to cheat their customers out of free-flow champers.
The reality is for me that I felt that not having alcohol from the earliest available moment in the day seemed to be a bit blasphemous. It is a wonderful start to the day, particularly that horrible gap between waking up and seeing the really cheerful early morning news and your first lunch time imbibitions. After all, it is our (us Brits at least ...) heritage. We use to drink beer in place of water ie "small beer" in towns where safe and decent spring water wasn't available. And it is our sworn duty to be mistrustful of water from a tap now. Isn't it?
I only give her English brunch to justify the champagne. It's under the radar. If I gave her champagne and corn flakes she'd smell a rat. So I do brunch and champagne and she doesn't start moaning about me drinking.
Cunning plan eh ...........?