Instead of messing with cellular settings, Airplane Mode? Will turn off wifi and cellular radios.
And can also setup an Automation in Shortcuts to turn on a Do Not Disturb Focus when Airplane Mode turns on: stop all Notifications from happening.
And more Automations (or Focuses): can setup a location based Automation (or location on DnD Focus) to turn on automatically when "at work". Or setup and use Work Focus instead of a DnD Focus.
Get a pretty much dead to outside world device.