Depending on how the images were loaded and what else you may have there
one option I'd read about, to save images that were backed-up or saved to the
iCloud Photos, would be to see about using google photos. This has been said
to have a means whereby images that otherwise had also though to be lost may
be recovered in the process of transfer.
However the amount or total capacities involved may not be practical to shift
over from say, iCloud Photos to google photos. Perhaps more than one other
archive may be needed to store the total difference you need to replace iCloud.
Your bandwidth may limit your ability move one archive to another online, even
though both are essentially going to 'cloud' accounts. ~ Do you have sufficient
offline capacity to archive the most important of this, off the Cloud?
Google offers (for a price) their version of online storage 'google drive' for
their 'google account' users; never tried most. Some of it tracks too much.
I see a few references from search engine results that may give you ideas...
This may or may not be something you could use; but may be worth looking.
Fed up with running out of free storage in iCloud? Here's how you can use the
Google Photos app to backup some of your data.
Google announced major additions to Google Photos at I/O 2017. Where do Photos+
iCloud Photo Library have to catch up, and should we be looking for from Apple at WWDC?
Download Google Photos ... Doing this saved me space from 3,000+ photos and ...
Simple and easy to understand unlike Apple and their photostream, icloud, ...
note other additional related items appear in 'duck-duck-go' results, using these terms:
In any event...
Good luck & happy trails! 🙂