Deep sleep beaglebone

What kind of deep sleep power dissipation do you think you could get with the BeagleBone hardware? I was thinking of something where you do a “suspend to ram” sort of thing, and keep a PRU running to tell it when to wake up. DRAM has to be refreshed, and the PRU has to have enough I/O still functioning to actually do the wakeup. This is for an application where I need much faster startup times, and where drawing a few mA continuously isn’t an issue.