If you have five year's worth of savings it's a no-brainer. Give it six months and then get back to employment if you don't succeed by then. Then work for anther 12 months and repeat the process if you have a new project.

As long as you are strict with yourself in only giving it 6 months, it should be fine. Tell everyone you know that this is your plan. If you don't get any traction within six months it's very unlikely that it makes sense to drag it out longer. Just cut your losses and move on.