Anyone know if there is any terminal + server side piece that, like terminology or iterm2, lets me inline plot in R, python over ssh? Linux or mac.

If you are running a Mac for your desktop (with iTerm2) and ssh'ing into a Linux machine. These work if you run them remotely as the image gets transferred through the SSH session:

https://github.com/daleroberts/itermplot

https://github.com/daleroberts/bv

Alternatively, for any other terminal emulator with Unicode 9.0 font support and true color support, you can use:

https://github.com/daleroberts/tv

This even includes Windows (using patched PuTTY) and remotely running 'tv' on a Linux machine.