Hello.
I'm interested in your project. Actually, i have 3 years of experience managing two clustered moodle sites based in Linux at Universidad de El Salvador.
If you accept my bid, this will be my procedure:
1. I'll check the current versión of your site, check the current versions of PHP, MariaDB/MySQL, check the current version of your plugin's site.
2. I'll set your site in maintenance mode, after that make a backup of the database.
3. If all requirements are ok. I'll download the new version of moodle, install the plugins, run the upgrade script's and turn off the maintenance.
PD: If you use alternates auth methods. It would be required use the local admin user(first user). If your site it's small the upgrade can be done in one work day. Preferably i would work from 6:00 PM to 10:00 PM GMT -6. On Saturday and Sunday i have more time.