Sleeping 2 hours a night is a sprint. Unless you are a superhuman, you can't sleep 2 hours a night for more than a week and still be more productive than someone on a normal schedule.

The point being, you can sprint in a crunch. You can sprint to meet a deadline next week. But unless you expect your company to be bought a week after you found it, you should probably be pacing yourself at least a little. Go ahead and give up work/life balance- for a medium-term project you can risk burnout- and go ahead and work 16 hours a day. But get 8 hours of sleep.