Sorry for the delayed response. I was very nervous about the recent issues with iCloud Drive docs being erased when wiping an iDevice. So I held off trying to do too much of anything. In the interim I did three things:
-copied everything from iCloud Drive to a thumb drive (do this monthly)
-copied everything from iCloud Drive to dropbox (so the latter is now used for backup rather than access)
-copied everything from iCloud Drive to a local drive, which is now also part of my Time Machine backups
Now that iCloud Drive is baked into the iWork apps I'll probably just leave this system in place.
You don't have any other "documents" except for Pages, Numbers and Keynote files ?
How did you organize, let's say pdf's ?
I'm curious about this as I'm looking for a implementation solution as well.