I want to disable further iCloud backups from one of my devices, but I don't want to delete the existing backup files already in iCloud. I couldn't find any way to archive iCloud backups the way you can do with iTunes backups, so the only way to prevent an existing backup from being deleted seems to be to not make a new one.
Some context [Taken from comments]
I recently updated to iOS 10, but don't much care for it. I do have a full iTunes backup of the device, but it's rather old. I also have an iCloud backup from immediately before the upgrade (I wasn't thinking straight). I plan to make an iOS 10 iTunes backup, then restore the iOS 9 iTunes backup, restore the iCloud backup to get my up-to-date data, then make a new iOS 9 backup. Then I'm in a better position to play around with iOS 10 if I decide to. I don't have time to do that right now, though, and I don't want my iOS 9 iCloud data to be overwritten in the meantime, since you can't restore iCloud backup data onto an older OS version.
My device is currently running iOS 10.2.1. Is what I want to do actually possible?