OK, I found the system displaying the boot messages
again, and was able to Ctrl-Alt-F2 to switch to
another console and run systemctl status kdm.service,
which said the service was up and running properly
for the last week.
I then switched back via Ctrl-Alt-F1 and suddenly
it was displaying the GUI again instead of the console
messages from the last boot.
What the heck is that?
Even if I wanted to, I have no idea how to switch
the display on console 1 to the text mode display
versus the GUI. How does this happen?
Intel driver bug maybe?
At least it seems like I can get back by switching
consoles twice :-).