Yes, my power strip is a surge protector type. Thankfully.
So, good news I think.
I powered up and the reboot quickly took me to the lock screen. No installing of updates happened. I checked Settings > Windows Update, and the update is still awaiting a reboot at the time/date I had set. But it had installed some Defender updates (apparently what it was doing when the power went out.) Defender says the updates were installed and I'm up to date.
Right now, things are behaving and I'm not having any freezing or slow loading issues at the moment. Maybe something got fixed in the DSM/restore health thing that was implemented with the restart?
I think I'll run a couple of the easier diagnostic tools listed here and then try the restart for windows updates if nothing comes up.