You can! Check out the demo video at 13m30s. It demos the X version of Emacs, but Emacs runs faster in '-nw' mode from the console.

http://www.davisr.me/projects/parabola-rm/

It's not emacs, but I've been enjoying iVim (1) on my iPad Pro. With `:idocuments` I can edit files in Working Copy (it opens the Files picker).

I also copied my plugins (Goyo for focus, etc) and config from my linux box.

1: https://apps.apple.com/us/app/ivim/id1266544660

I'm planning on trying to do that as soon as I get mine. Being able to use org mode and org roam would be a huge plus.

Can we imagine this device to be something like a mix between the Kindle reader combined with a tablet running Linux?

That's what I hope! And looking at the rehackable GitHub repo I think it's not far fetched