Downgrading games / installing old updates

There is a mod I want to use on Xenoblade Chronicles 2 that only supports up until version 2.0.0. However, the most recent version of the game is 2.1.0, which is the version I have installed. I could uninstall the update with tinfoil and go back to 1.0.0 but Xenoblade 2 got so much more content and fixes over it's lifetime that it's a much lesser game without.
The problem is that all my usual sources only carry the most recent update of most games, so I am unable to find the update I need. Is there any clever way to obtain the 2.0.0 update?