Probably the biggest impediment to early retirement is health insurance. It is expensive prior to hitting age 65 and to be eligible for Medicare. My wife and I both have big medical issues too like your wife's, that are not conducive to longevity. I decided to retire at age 50 from my big stressful career job and then took several much less stressful part time jobs to keep our retirement nest egg intact and growing. We also shrunk our lifestyle to live within our means. We had no kids at home and health insurance wasn't an issue for us. We also began our RVing lifestyle at that same time.
Seven years later (age 57) I had a crippling, near fatal, heart attack that forced me into full retirement. Now, five years later we are still enjoying the fun of RVing and the blessings of grandchildren. My wife also pulled the plug and retired last year. Right now, our lives are being held up because we are now caring for her 89 year old mother who is in the last stages of her life. Once free, we are really hoping to do some extensive travelling to enjoy our RV and see this great wonderful country. If you have the means to do this now, I highly recommend it.