okay figured it out.
with zero tweaks to anything, my 5750GE is idling with a package power between 5.25 and 6.25 watts, roughly. the tool I'm using ('turbostat') seems to think that's at between 3.2 and 3.6 GHz give or take, with all cores mostly idle.
this is useful, I eventually plan to decrease the base clocks on all these little 35W machines of mine to save some power, not just the Dell with the USB-PD decoy power dongle...