Depends on the issue, during Cyclone Gabrielle here in HB with extended no-power it was paper, but there was no students, no school with no power (battery backup supplies long depleted by that time)
I had a stand-alone copy with Chrous/N4L just for mailouts but mostly useless with varying parts of town without power, cell sites knocked over etc.
Limited social media connections played a better role here, vs a push service like email or app.
I do have deployed a MDM offline WPA2 network profile ready to go on a standalone device with some old Ruckus AP's that can act as a FM server and restored latest backup. (dirty dns hack to point clients to a different server)
This is only in place if the server room is lost to fire/flood, taking out chorus, n4l/fortigate etc. Only for local admin staff so its pretty minimalistic.
I think losing our core network, ie is probably the worst scenario (where the classrooms are still all fully functional, so students can attend)
Matt