I use the TPS76050 (TPS76033 for 3,3v) , its 50mA out, Iq ~ 100uA.
For nanopower applications you might want to look at some nanopower voltage references, many can supply 5v ~ 10mA
One thing to check on the data sheet is how the queiscent current (= ground leg current) changes with load, some parts may add 10% of the load current as quiescent.
If you only want approximately 5v then consider using a depletion mode mosfet , the VGS is -1v so use a 4v low current, low leakage zener diode. The attached figure has a 10k resistor, so Iq = 100uA. A bigger resistor will mean less Iq at the expense of more temperature drift and worse regulation. With a BSP 149 expect 100mV regulation up to 20mA and < 100mV droput voltage.