I knew one guy in a fire zone - He did his house up all fire resistant materials (Read things like block walls, etc, complete with the wide borders etc) and his secret (he was in a similar situation to the OP - no trees, wide grass, then fields) - his garage had a nice cat bulldozer he took from his company when he sold it - he said "I can clear a NICE firebreak around my place in an hour or so, and WILL do so, if needed"