I don't know.

Everytime I switch off auto update HERE, the game finds a way to update itself. And it then reverts auto update to "on". It's up to a point where you wonder what's the real use of the on/off switch.

On second thought, unplugging the connexion seems the best course of action. No internet, a offline PC, there's no way the game can know when a patch's available.
In a second time, you'll need another computer for web surfing.

I think I'm on to something.