I usually find that Unix terminal applications work reasonably well in large print as long as the terminal itself can. However, increasing the print size usually means that fewer rows and columns are available, and some applications don’t work very well on terminals with fewer than normal rows and columns. This can sometimes be fixed by configuring the application. Here are some of my dot-files for this and related fixes:
For GNU/Linux top, try pressing f and turn off columns you don’t really need (try h, i, q, t, m, and perhaps turn off e and turn on d on single-user systems), press c to toggle extended commandline and press W to write to .toprc. Mac/BSD top is less flexible.
On modern GNU/Linux distributions the console font size is quite small. You might be able to go some way toward enlarging it by using this .console-setup and putting setupcon in your .bash_profile, or if you don’t have setupcon then try setfont /path/to/TerminusBold32x16.psf.gz.
On FreeBSD the command is vidcontrol -f /usr/share/vt/fonts/terminus-b32.fnt but to make this work in FreeBSD 11 and above you also need to put hw.vga.textmode=0 into /boot/loader.conf (although at least text-mode on means the starting size is not quite as miniscule as became popular on GNU/Linux).
For fonts larger than 32px (and for CJK), on GNU/Linux you might be able to install fbterm—here’s an example .fbtermrc, and if you want to turn off anti-aliasing you can try this non-antialiasing .fonts.conf (on some systems it needs to be saved as .config/fontconfig/fonts.conf) but some versions of fbterm corrupt the display when anti-aliasing is turned off.
If the machine has sufficient resources, you could just use X11 with a terminal program set for large fonts.
All material © Silas S. Brown unless otherwise stated. FreeBSD is a registered trademark of the FreeBSD Foundation. Linux is the registered trademark of Linus Torvalds in the U.S. and other countries. Mac is a trademark of Apple Inc. Python is a trademark of the Python Software Foundation. Unix is a trademark of The Open Group. Any other trademarks I mentioned without realising are trademarks of their respective holders.