How can I change the cache path for npm (or completely disable the cache) on Windows?

You can change npm cache folder using the npm command line. (see https://docs.npmjs.com/cli/v6/using-npm/config#cache)

So you might want to try this command :

> npm config set cache C:\Devel\nodejs\npm-cache --global 

Then, run npm --global cache verify after running this command.