I don't have a spouse to depend on, but I am FI and just working until November, when I qualify for lifetime medical.
Being a federal employee, it would probably take an act of Congress for me to lose my job Monday morning. Even if I did, I would probably have a lot of opportunities to continue working at some other federal job for the few days left until I retire. That might require relocating, but I would have to do it. I would just take a suitcase and my laptop, drive there, and rent a studio apartment there until November. I would sleep on a blow-up bed from Wal-Mart.
But let's assume that somehow I lose my job and there isn't another job for me.
First, I would probably CELEBRATE MY RETIREMENT!! I'd sign up for COBRA, which I believe lasts for 18 months and would take me to age 62. By that time, I would have sold my house (I hope) and I would be living in Missouri. I would then sign up for whatever high deductible medical I could find. Missouri has a high risk pool, if necessary by that time. At 65 I would sign up for Medicare parts A, B, and D if they still exist.
Since insurance/Medicare would be more expensive, I would have to make room for it in my budget or else do without. But going back to work? I wouldn't even think of it unless it was another federal job from now until "ER-Day".