I don't think it's that unlikely. It wouldn't really be bezel-less either. Based on some official dimensions I got from Apple along with some math, I did a quick mock-up of what a 10.5" display would look like. It's not 100% accurate (the screen "active area is larger than my calculations for a 9.7" diagonal at a 4:3 ratio), but you can see that all you need to do is rearrange the camera and maybe remove the home button (which is supposed to happen with the iPhone 8), and you can easily fit the current form factor.
That's my dream machine (10.5 screen in 9.7 body)...I hope Apple surprises everyone and does it later this month or in March rather than _after_ the iPhone 8. But somehow I think I'm destined to be disappointed...