Reminder for any iOS user that needs instant iCloud Photos backups (instead of manual monthly), get a Mac Mini, enable the Photos app, disable optimize for storage and keep it on to keep your memories safe. Always check the recently deleted folder on the Mac every month since iCloud by design is a two-way sync and not a backup, unlike most clouds that are one-way upload (doesn't touch your local files).
Cold storage backup every month using the photos on the Mac should be easier as well.