I'm talking 12 years ago, but had my Butane system changed to Propane by a 'Calor Gas man'. His opinion was that you could use Butane in a Propane bottle but not the other way round. You'd need to carry two regulators, but not a major problem to swop them over. Just check your burners/oven will function with Propane. If you're going long distances I'd go for Propane (and invest in a pressure cooker).