How to drive a P-channel MOSFET with a MCP1407
My question is, can I put 15V in the GND pin of the MCP1407 and 30V on
  Vdd?


Yes you can but there is always a little demon in the detail - you have to drive the MCP1407 from a signal that is 15V lower and this takes a little care to ensure edges are maintained and you don't over-stress the input of the driver - this can sometimes happen at power up or power down so be aware.

Alternatively just use a high-side FET driver that uses boot strap techniques and an internal level shifter. Maybe the MCP14700: -