I would be really annoyed if I had to leave it now, because I think we're maybe a year away from having a really great solution in our market.

Your answer is sitting there in your words. Keep your day job for a year or a year and a half. Then ask yourself the question again.

If you need a project, focus on cutting your expenses. Learn to budget. Learn to cook. Pay off the credit cards. Move to a less expensive apartment. Every dollar you cut from the budget is not just a dollar you get to save for when you're self-employed, but a dollar that you won't be spending when you're self-employed, because you won't be in the habit of spending it.

If "storm clouds are on the horizon" then there's a chance you'll get laid off in the next year. Then you can collect unemployment while you're looking for a day job that doesn't restrict your extracurricular activities. If you quit now, you'd have to do that anyway, without the benefit of the insurance.

I would listen to the lawyers and not-a-lawyers in this thread: Don't do startup work while you're still employed at the company.