More Words, Deeper Hole

I'd say a person is closer to 0.15 m^3 (1m waist circumference, 2m tall) - but close enough. Our volume estimates are around the same (1000 people in a 757-767 sized fuselage, depending on how much baggage they want to bring along).

Since the hibernating people are running with a metabolic rate that's 10% of an awake person, their O2 demand is similarly reduced. My assumption is that their O2 demand can be satisfied at a lower atmospheric pressure. If I have time I'll go digging around for a graph of O2 saturation versus ppO2, and see how low of a pressure you can go and still satisfy a hibernating sea-level-acclimatized human.