Longest I carried my 5x7 was 2 miles on flat pavement in the Keys and did 3 exposures.....I had my girlfriend carry some film holders to lighten the load, I also had a 5D d*****l and ultra-wide with me.

Was worth it despite dropping the lens and lensboard and having my shutter buy the farm, if I can't sort it out this week it will be in the hands of one of our trusty members.