FWIW, I came accross this thread about the dangers of driving with LP gas on.

http://westfalia.org/eve/forums/a/tpc/f/64160255/m/4566040411

You may have to be a member to read, not sure, but lots of great info on the site.

I have my fridge connected to the auxiliary battery and hooked up in a way where it doesn't cut off when the engine is off. For the shortstops for gas, or snapshots, I don't worry about running the battery down. Once I am at my final destination, I then switch over to propane. I have heard that the cooling is more efficient with propane, versus the other methods, but I've also read a thread where a gentleman did some testing and found that not to be the case.  See: http://www.vanagonauts.com/index.phtml?catid=139

Having a secondary fan on the interior of the frig, as well as replacing the stock fan in the back helps greatly. Not telling anyone they shouldn't drive with their LP gas on,(it's your life) but have to ask if it's worth the risk, when driving on battery pwr is free. There was a rather gory photo associated with the article, where a van burnt down to the metal within 20 minutes from a propane leak!

Best,

Troy