Thanks for pointing me in the right direction! After a few more steps I was able to get this working. After update-initramfs, there was no change. I then ran:
$ sudo prime-select nvidia
After a reboot, it went to a black screen again. I used ctrl-alt-f3 to get to the console. I was then able to run nvidia-smi and the driver was loaded correctly. I then assumed the problem is that it is trying to use the Tesla T4 as the display device.
Afterwards, I found instructions on how to use the integrated graphics unit on Ubuntu 20.04, and everything is working:
First:
$ sudo prime-select on-demand
Then, I followed the instructions here to select the intel: