[msandford]

I had this problem on a low power design. We were making an industrial temperature sensor for something that moved and we needed to run on battery.

What I ended up doing was using a second voltage regulator with an enable pin for all the accessories. When the MCU wakes up it turns power on to the accessories and waits for things to stabilize, maybe 1ms or so. Then it does what it needs to do and before going back to sleep turns all the accessories back off.

Costs you a few extra parts and a second voltage bus and the hassle of programming but it turns "small quiescent draw" into essentially zero. Maybe the regulator has a bit of leak but it should be pico amps or less.