I think that this sounds more like being the first employee of a company rather than a technical cofounder. When recruiting the first few employees, this is exactly the pitch that I give to them but if you are going to be a cofounder, then reasonable hours, working environment, etc. are really up to you and the other cofounder. Thus, you make what you want. The point about "reasonable guy" is thus paramount. In fact, I would argue you need much more than reasonable.