How would you regulate/use 60V/1A or 12V/100mA to get ESP's 3.3V/~300mA?
How would you regulate/use 60V/1A or 12V/100mA to get ESP's
  3.3V/~300mA?


There are many options from many main chip suppliers such as this one from AD/LT: -



TI have offerings of a similar nature too.