The real question is about the disc. I am assuming PS4, and from what I remember, this requires a new purchase of the game, however, the same ESO account should be able to be used. I think that what you have to do is delete game from the console (disc version), then buy a new digital copy of the game and install.
So, if you go that route, you purchase "Collection: High Isle™" or "Collection: High Isle™ Collector's Edition" after uninstalling ESO completely.