How to modify a voltage regulator to make it very low quiescent current?
Low-power design is difficult, and I refer you to this detailed article I saw recently; you should read it in its entirety.

http://www.ganssle.com/reports/ultra-low-power-design.html

Some salient points, mostly from the above article:


a zener-based regulator is incredibly inefficient and will kill your battery faster even than the 1117.
why are you using two batteries?  The usual approach is to select a micro that can run anywhere between 2V and 3.6V (which is most of them), and directly connect it to the battery, but...
decoupling capacitors are also very leaky.  Even if the micro runs at low average power and you get rid of the regulator and all its leakiness, the capacitors become a problem.
supercapacitors are super-leaky.  Don't try using one to store a bit of temporary charge to avoid regulator overheads, because it's probably leakier than the regulator.
batteries are terrible.  Drawing current from them makes them look dead before they really are, so you need to be careful with how your micro ramps up its power consumption coming out of sleep.