How strong must a business plan/startup be before you would consider delaying your undergraduate education by a semester (possibly indefinitely) for the sake of

How strong must a business plan/startup be before you would consider delaying your undergraduate education by a semester (possibly indefinitely) for the sake of pursuing the opportunity? To narrow this down, assume you're a sophomore in a well-known college and it's a 6-7 person startup with plenty of big-name backing (no, of course this doesn't apply to a real-world situation I'm in :-D).