Chan-Ho Suh answered this in a comment:
Hi Luke. I took a look and see nothing amiss (unfortunately). The
usual problem with the Nvidia prop driver is that the Plymouth splash
is the wrong/low resolution, but in your case, it can't even boot in a
lower resolution, which is odd. Anyway, the usual way of fixing the
former is to uncomment
#GRUB_GFXMODE=640x480 and set it to the
appropriate resolution. So that might work for you too.
To uncomment a line in a configuration file like
/etc/default/grub--which is the file to be modified in this situation--remove the
# at the beginning.
/etc/default/grub, the command
sudo update-grub must be run, to apply the changes.