Emergency Mode or Similar Approach

[shenry11151]

Hello,
Is anyone actively utilizing some sort of "emergency mode" for their contact center queues or know the best approach for certain situations?
We have situations where our HQ may need to evacuate the building, or a power/network outage takes place and wanted to find out the best way to handle that when no agents are available for incoming calls.
I'm hoping the best option is not to have them all go to "Not Ready", but if it is then what is the best way to change the overflow/voicemail option quickly without logging in and managing each queue.

Thank you!