Wide input voltage range buck converter/circuit to 3.3V 150mA
Is it possible to break your load into two parts: an accurate low-current supply that is used for the microcontroller and any analog stuff; and a less accurate higher-current, higher voltage supply that powers things like relays and such?

Many of my products are built this way - my 5V rail needs to supply only 5 to 10 mA and the unregulated supply at whatever voltage I'm working at powers the multitude of relays that many of my products use.  I do PWM on the relay coils as necessary to keep the average voltage at the rated value as the input voltage changes.

I have a simple but effective AC Phase Control power supply regulator that works well from about 16Vac in through 230Vac in.  But it's good for only AC input (not DC) and it can supply only about 75mA.  That doesn't meet your requirements.