I think a BWR with manual-move double chainring and replacing the supplied pedals and bringing a wrench to remove the left pedal would last the longest.

Another key thing is to rethink all the non-bike gear, shrink its weight and volume. Seriously......
If I'd not been fit, I'd probably not have coped. Being fit, the man was stronger than the machine but if didn't have the fitness the man would not have coped.