I finally got around fixing the quiescent current problem. I slapped my forehead not thinking about it before, but the answer is simply to make use of the quite extreme 1:20 duty-cycle of my application. Dynamically switching the opamp on/off when needed reduces current consumption accordingly. I also found the OPA454 opamp with a much better Iq and has an enable option which made interfacing to my 3.3V logic simple.

Thanks for all the help and insight, I learned much about opamps along the way.

I finally got around fixing the quiescent current problem. I slapped my forehead not thinking about it before, but the answer is simply to make use of the quite extreme 1:20 duty-cycle of my application. Dynamically switching the op-amp on/off when needed reduces current consumption accordingly. I also found the OPA454 op-amp with a much better I_q and has an enable option which made interfacing to my 3.3V logic simple.