Just bought a Dex Station. If Emacs runs well enough then it will be a lifesaver.
What this "Linux on Galaxy" thing will provide on top of Termux is X (or Wayland?) and probably a bigger selection of software.
Nowadays I simply use JuiceSSH and mosh to connect to my main computer. I would like to have Emacs in my smartphone even while I don't have mobile signal though.