Make a backup of your phone on iCloud as well as in iTunes.You can download all your apps to iTunes then create an encrypted backup in iTunes. Doing that will allow you to set up your phone as it was before installing the OS anew.
I make a habit of doing both kinds of backups regularly, as well as using a program called iMazing, which allows me to have numerous complete or custom backups of my phone.
Always make a backup of your backup.