If you’re on Android then you can use Termux (via F-droid) to get ssh capabilities. I think there is also a different iOS app, but I’m no expert on that OS, so I can’t tell you its name. If you have a smart phone then you might have a ssh capable system after all
Mobian has an amd64 image available. If you are looking for a “tablet” tablet experience rather than just desktop gnome with an on screen keyboard then that is going to be your best bet.
In terms of DE I would stay with GTK enviroments because GNOME circle has created a pretty extensive environment of apps that feel native there. Both PHOSH and GNOME mobile offer basically the sane experience so you should try them both and see, which you like more in the details
https://mobian-project.org/
Edit: here is the install guide: https://wiki.debian.org/Mobian/x86