Our plan is to have a healthy emergency fund (3-6 months of total expenses) and that usually fixes those problems as they arise, as long as your don't lose your job, the car breaks, the roof blows off, and all your teeth fall out at the same time. Planning for catastrophes by planning for the absolute worst case is very difficult, and it may cause you to save less than practical for early retirement.
Once we have our home paid for, we may use the MMM method of establishing a line of credit on the house for such emergencies, but I refuse to do that until we have 0 debt.
It really is what makes you sleep easy. It sounds like you have an excellent handle on it though!