What's your side project? (Can you describe it in general terms without specifically identifying it?) How well might it align with an existing company? Can you think of a company that would pay you to work on it, either full-time or as a major component of your job? Have an off-the-record conversation with people associated with that project who work elsewhere; see if someone might hire you. (Consider both the "doing it as a paid project" angle and the "Open Source it and get a paycheck to work on it" angle.)

If your side project is something people want, getting a medium or large company to pay you to work on it seems entirely plausible.