The true value of a hackathon is twofold (imo)
- you don't have normal office interruptions and the like and can focus on one thing for an extended period
- you get to meet interesting people and exchange ideas
I think just focusing on that and mostly ignoring the "extremeness" of hackathons would be awesome. Instead of thinking "how can I code on for hours" a better focus would be "how can we generate a very productive and pleasant environment and still reap the benefits of hackathons".
For example, if it's a biggish place, childcare for parents would be something I'd think about before diving into how to get more coffee to the venue ;)