Standard fire insurance would only cover it if you were actively fighting a fire on your own property, same as with a Cat or any other machine. Cross the property line on to the neighbors or road allowance and insurance is null and void when fires are involved that you intentionally drove into or are working close to. Of course that don't mean that one don't just go ahead and do it anyway under some circumstances, but you better hope to helll you don't suffer a crippling breakdown, cause that could get extremely expensive fast. The part that always pisses me right off, is even if you are trying to head off the fire before it gets on your property, once off your own land, you have no insurance, to me that is just plain dumb.
Contracts are made to be broken, a handshake is the law of God.