Nowhere near as valiant as you chaps I used to ferry aeroplanes - namely the Twin Otter - from Downsview, Toronto and one one occasion I brought my CAA Ops Inspector for the ride. I planned to transit at fl200 ish but John Mitchell was an inveterate smoker so I made for the occasional nicotine break for him and switched the oxy system off. He started drinking fizzy drinks as well, probable dehydration from a night in Gander. The toilet bin was right down the back and he had to climb over the nine drum quick disconnect fuel system. My big worry he would become hypoxic as the only breathing set was in the cockpit. This went on for about six of the eight hours or so with a cigarette btween each of the 90 minute Pee breaks.
We did a low ils overshoot from Kef into Reyjkavik and John offloaded all his salmon into the hotel freezer. Approaching STY the next day he realized it was still there so I believe the CAAFU 125 did a couple of circuits at Reyjkavik a few days later and brought the salmon home. Quite happy days ferry flying.