Csound1 wrote:
Storing them in iCloud uses the same amount of internal drive space
?????
If you delete them from your computer then they take up no space. Theoretically you can re-download them when you want to view them again. They are in "iCloud" but taking up no space on the computer except for the individual movie one is viewing at any one time. Apple uses the terms "iCloud" for pretty much any of its online services, including the iTunes Store re-download feature.
However, this is not such a great idea because if a studio decides they do not want to permit re-downloads, or simply wishes to stop distribution of an item then you're stuck. Re-downloading is a convenience but only multiple copies on local storage is a guarantee.