couldn't you setup a router to use a static ip for them?
It was a headless server and it normally runs for several months without a reboot. They just abruptly shut off the power and tried to attach a monitor in order to try to change the IP address. (If they had used VNC instead as intended, it might have worked.) Then they called the ISP and begged them to temporarily restore the old address - but the file system was already destroyed at that point by the power interruption.
After I got home from the funeral and heard what happened, I had to drive over there, which took about an hour, reinstall the OS after the quick rescue attempt failed, restore the data, etc. I suspect the disk drive was writing a cached file catalog when they pulled the plug. I could have fiddled with fsck for a while and possibly fixed it, but it was quicker to just wipe it clean and start fresh. I see some sectors marked unusable now, so fsck may not have worked ultimately.
I have shortened the DNS cache times for an orderly midnight transition in a day or two.