I would set this up using two user accounts.
A "shows" account with everything iCloud disabled.
A "niCloud" account that is logged in to iCloud and other services as needed.
Between shows or whenever needed, log into the niCloud account and run a script that copies (or rsyncs) the shows between your iCloud Drive and the /Users/Shared directory.
Then run a show from the shows account.
You could use a login script to forcibly disable WiFi, Bluetooth, anything you don't want running really on the shows account.
Alexander