Not sure what happened yet. I happened to wake up early and saw a note in our Telegram group that no Simutrans sites were loading - thank you Roberto.
Got to the computer as quick as I could to troubleshoot. Unable to connect, no response to ping. Tried two power cycle twice via the datacenter's control panel, no luck, so opened a ticket.
Datacenter cycled power and we're back up.
Meanwhile, I've found notices of a couple of my sites being down (from Jetpack) from last night - but alas, some previous troubleshooting in Office (Outlook stopped loading email folders) led me to remove that email account and I hadn't re-added it, and had not happened to add it to my phone.
THAT has been rectified as well, so hopefully, were this to happen again, I would get better/quicker and even advanced notice and be able to react more quickly. meh.