I started an update before leaving this morning.
When I returned the update screen and whole laptop were frozen (crashed); it looked like half of the updates had been downloaded.
There are no network wifi links now (it usually lists many), no sound despite settings, The clock is off by roughly 5 hours.

I dual booted Win10; wifi and sound are working there.

I don't expect I can try
pkcon get-updates
without a network

I did try
pkcon repair
and it ran without error but no change.

What short of reinstalling might fix my system?

I could wait no longer.
I tried to restore an image made in March with Clonezilla.
Although it was "restorable" Clonezilla had I/O errors and failed.
I then tried to install Neon, but each time it crashed when it ran into problems with EFI and grub.
Grub actually lets me try to boot but no GUI opens. I tried startx, kstart, kstart5 variants without success.
I will work on getting it fixed some other way after exploring more and trying more.
That ends this part with it NOT SOLVED. I will go to another subforum.