Alright! Networking issue solved (rebooted router). I am now able to access pve via browser.
I set all the VMs to not start at boot, and then went back into the BIOS and re-enabled virtualization.
PVE host booted fine.
Next I went one by one, changing VMs to start at boot and testing to see if each interfered with a reboot.
No issues were discovered this way.
The whole server seems to be back in functioning order, the mount points are re-mounted, and no data is lost.
Now to figure out how to prevent this from happening again....