Ian999 wrote: …However, every option I see about turning off iCloud in my settings tells me that the local files will be deleted!
Right-- if you turn off iCloud Drive, then the local files in the Documents and Desktop folders will be deleted, and new empty Documents and Desktop folders will be created in your User folder where apps expect them to be. The files remain in their folders at iCloud.com, however.
If I were doing this, I would create a TempDocuments folder and drag everything from Documents into it. That should leave the iCloud Drive Documents folder empty. When the new local Documents folder is created, I would drag your "temp" files there.
Keep in mind that the iCloud Drive folder on your Mac is just a normal folder-- it's just that stuff in it is copied to iCloud.com. If you use "Optimize" storage thing become a bit more complicated but, really, it's just a folder on your Mac. You can see this:
Understanding iCloud Drive - Apple Community
You mention that you "keep these files backed up on iCloud," but iCloud is not a backup service, so that sounds like a misunderstanding of either "backup" or of "iCloud." iCloud's purpose is to synchronize files with other devices. If that's not what you want, then you may need to re-think your use of iCloud.
