eNom data center migration mistakenly knocks sites offline

eNom domain registrar, which manages over 15 million domains, is experiencing a botched server migration resulting in all domains using its servers being down for over a 24 hour period.
Maintenance window has been extended multiple times, and the issue is still ongoing.

Customer websites are down.
Emails are not delivering.

"What's absolutely nuts about this is we can not change our NameServers due to eNom itself is down (going on 24 hours now). Never in my life have I been in a situation where I can't route around network issue at the root domain records level. We are totally trapped!"
eNom customer

One of the affected websites is Certitudes, a geocaching puzzle checker, which creates great difficulty for geocachers around the world.