@Kvnklly
Okay so I've done this and the actual solution is USB tethering of a mobile hotspot. Works like a charm.
@Kvnklly
Yep!
The first time I tried, I was luckily going to be installing the OS on a USB (rather than the mac's storage drive, which was borked), so I just booted the USB on another computer, installed the driver, then moved it back to the Mac.