The v5.0 kernel introduced a “high-dpi” font, FONT_TER16x32, which is simply twice as big, as the regular kernel font. Once enabled, one can update
$ cat /etc/default/console-setup | grep '^FONT' FONTFACE="TER" FONTSIZE="16x32"
And voila the ttys have readable text now! We are in progress backporting this feature to all the supported kernels on Xenial and up.
It means that all of Gnome/Unity, Plymouth, and Kernel will have high-dpi support. It would be great to add the large font support to Grub too, and thus complete the high-dpi setup.
I am not sure if we should default to the extra large fonts, or not, across the board. On non-interactive systems it will not matter, and interactive laptops will welcome readable fonts.