Maybe this hekps if you are up to using Minion addon manager within linux:
http://www.esoui.com/forums/showthread.php?t=2217
And I've found a tutorial about ESO on Ubunto/linux but it is german.
You might translate it via google translation or website translations:
https://www.elderscrollsportal.de/th...u-14-04.49719/
I'm no linux user so I do not know where the "windows user directory" is mounted within linux.
Are you playing via WINE windows emulator or is there some linux version of TESO available?
If you are playing via WINE I thing the directory of the windows addons e.g. c:\users\yourusername\documents\Elder Scrolls Online\live\AddOns would be the one to mount within linux/ubuntu so the game can find it somehow.