My workstation is running a bleeding edge emacs full-screen in a
dedicated display.  When working on a server, from time to time I use
programs that invoke the shell EDITOR.  I can set EDITOR to emacsclient,
but that will just open emacs on the remote machine, which is not what I
want.  I want whatever editing job needs doing to pop up in my local
fullscreen emacs.

I can ssh to the server, so obviously I can use my local emacs to edit
files there via Tramp.  And server.el already has functionality for
listening on a TCP port, which is easily forwarded over ssh (there are
various hacks out there for forwarding unix domain sockets as well,
which I haven't tried).

The missing piece is simply a way to let emacsclient instruct emacs that
the files it passes to emacs are remote.  Attached is a patch for your
consideration which accomplishes this.

Additionally, it would be handy to have some tooling for conveniently
forwarding the correct ports and setting up EDITOR with the correct -T
option on the remote machine, but that is outside the scope of emacs
code, I think.