Let agetty (or other) switch off the laptop screen after a short while on non-UI linux

Using an older laptop as a small server with no graphical UI/login, it has an agetty running on the system console, i.e. the laptop screen. Since I login almost always via network, there is no point having the screen switched on. It should be off until I hit some key. Can this be done? The following are non-options: - not running agetty, because I want to keep it as a fallback in case I cannot log in over the net anymore. - setterm cannot be used, because I would have to log in first - setterm --blank says "terminal xterm-256color does not support --blank" :-/ - vbetool linked in some answer wrecks the display to show garbage and cannot switch it on any more on my laptop. This answer says the console should only be started on demand, but clearly when logging in via ssh I see two agetty processes and the laptop screen is on showing the login prompt.