Can I move all of my synced documents, folders, subfolders onto the cloud?

I have had a CC subscription since 2015. I started out using the cloud storage as it was set up then. When the new "cloud documents" were introduced, I saw no way to move all my files, which are myriad and intricately organized, onto "cloud documents" at once, so I never use it.

I recently upgraded my computer, but it has a smaller hard drive than my last. Tonight, I tried to upgrade my iOS, but I was unable to because I don't have enough disk space free. When I look at what is eating up all my space, it is my CC image files.

How can I make my files stop taking up all my disk space, without deleting them? Can I migrate them to "cloud documents" (one-by-one is NOT an option)? If I do, will they still take up the same amount of disk space?

If I keep the documents as "synced files," is there a way to have a smaller fraction of them readily accessible on my computer and taking up space, while the rest stay on a cloud?