Thanks for finding that for me, TobiSGD!
No joy, so far, but some hints perhaps. Here's what I did:
1. I added these lines to /etc/default/grub and ran grub-mkconfig -o /boot/grub/grub.cfg. Still the type is tiny.
2. I commented out the line with 800x600x24 and uncommented the line already in there calling for 640x480 and ran sudo update-grub. Still the type is tiny.
3. I appended "915.modeset=0" without quotes to the end of the "GRUB_CMDLINE_LINUX_DEFAULT="quiet"" line. Upon running sudo update-grub got an error message.
4. Re-edited to put a comma in front of 915.modeset=0; still got error message.
5. Put in a second GRUB_CMDLINE_LINUX_DEFAULT= line and put in the 915.modeset=0 line here, and finally update-grub ran without complaint. When I rebooted, got a lot of error lines scrolling too fast to read--but in a larger type. (Yay!) But then it switched back to the tiny type. (Boo!)
6. Tried commenting out the old GRUB_CMDLINE_LINUX_DEFAULT="quiet" line, but still got the scrolling larger type switching to tiny.
7. Tried rebooting and holding down shift key so I could get the grub menu so I could run the "vbeinfo" to see if I just need to specify a different resolution, but got no grub menu.
Any thoughts on what I can try next?
Thanks for helping me, TobiSGD!