Glad you guys are back safe and sound.
Did you see black smoke out the back while driving? I've just never heard of a 3B eating so much fuel before. Even when I'm towing my 16' camper trailer with my 2.4 turbo (similar fueling to 3B) I get 16l/100km (9000lb Gross weight truck/camper with huge wind resistance).
There must be something going on here. I'd say, check injection timing, test your injector spray pattern, pump fuel setting, tire pressure, brakes dragging, transmission/transfercase/rearend oil viscosity/quality, etc.
If you pull your injectors, I have a tester here at work. I don't mind helping you test them.