The setup exe I think can be anywhere, but the folder with zips needs to be called "OculusSetup-DownloadCache" (with any trailing letters removed) and put in the C: root folder. However, once the installer realises there is a newer version after checking online, it overwrites this folder with newer zips and ignores what was already there.
So I need to invent a time machine to go back to 2017 and install the software then, then. I can see why VR take-up is so low. tardis' not included.