I think that you have two options.
The literal answer would be to pass
video= to the kernel. For example, you could pass
video=720x400 to run the framebuffer at a 720x400 resolution, assuming that the specified resolution is supported by your hardware. See modedb default video mode support and Kernel Mode Setting: forcing modes. I'm not sure how this would interact with X or Wayland.
The better answer is probably still to set a larger font for the console virtual terminals, as modern displays provide the best experience when run at exactly their native resolution, whatever that happens to be in your case. You mentioned in a comment thread that you can't make the font much larger, but I suspect that you're trying to also keep the
Fixed font. Try editing /etc/default/console-setup to indicate something along the lines of
and run /usr/bin/setupcon to apply the changes. (See also setupcon(1) for some command-line switches to make the changes less invasive while experimenting.) There's also Terminus (non-bold) if you prefer that. To determine the available font sizes, you can either run
dpkg-reconfigure console-setup and go through the guide, or look in /usr/share/consolefonts; for example, on my Debian Bookworm system, I have these Lat15 TerminusBold fonts available:
which would map to size values of
32x16. On present-day Debian, these fonts are provided by the
console-setup-linux package which you should already have installed on your system.