Very interesting. More people are downsizing from the 11" Pro than are keeping the 11" alongside the Mini 6. By contrast, among owners of the 12.9" Pro, more people are keeping their 12.9 than are downsizing from it.
I'm in the latter group, keeping my 12.9 and bringing on a Mini 6 to use as a second iPad. This suggests that the Mini 6 will cannibalize iPad Pro 11" and Air 4 sales more than 12.9 sales.
Reading in bed, with a nearly 13" iPad is... Barbaric? Wait, um... Ill advised? It's 'huge', the Otterbox cover is huge, and together, it's heavy, and it's huge, and the cover is so large, there's almost not enough room in bed for two people, and the cover! (And after my original 12.9 refused to uniformly dim the screen, and had a dead pixel, and was replaced, the screen at least behaves, but I wonder if it too will go too bright like the old one) I have been cheating on my 12.9 with the iPad Mini 4, and finding, oddly, that the screen seems 'smaller' (Too small?). I read both without my glasses, and reading the large one is a bit much, but, heck, I don't know. Maybe I should cancel the Mini. I don't know. I like the size of the Mini, but... HAH!!! Apple, I'm sure, wanted us to face this conundrum. 'Just buy both' would be their likely answer. *sigh*