Sure. PowerStrip might be able to do that, if you could bind a hotkey to a particular resolution, with custom sync polarities.
Back in the olden days, monitors used to use sync polarities to indicate which resolution was being used, back in the days of multiple-fixed-freq monitors, before the introduction of computer-controller multi-sync monitors. So video cards still have that ability. Nowadays, most video cards output (the same) particular sync polarities for multiple different resolution video-modes, and use the alternate sync polarities to signal to a DPMS-compliant multi-sync VGA monitor to switch to a different power-save mode. I think that you have to cut the syncs altogether to get the monitor to enter power-down rather than sleep mode, but it should be possible.
Alternatively, you could have a 3rd-party app respond to a hotkey, and then send a power-management request to Windows' itself, and then it would send it on to the video drivers, and they would "do the right thing", assuming that you had your monitor properly installed in Windows'.