Install Apple Devices from the Microsoft Store. It brings the iPhone USB network driver and the service OwnYourProxy asks for phone names.
Install OwnYourProxy
Run OwnYourProxy.msi from the download page. It installs the app and the ownyourproxy command for your user, no administrator password.
Plug in the iPhone
Turn on Personal Hotspot, plug the iPhone in and tap Trust.
Keep Windows on its network
Run the routing fix once, in an administrator terminal. It gives phone adapters a high interface metric, so Windows keeps its normal network for everything else.