I would have no employer as I would live off investments.
As long as I can prove lawful residency (example - passport and a one year lease agreement) I should be able to get full coverage for free.
"The NHS is a residency-based healthcare system and eligibility for free NHS hospital
care is based on the concept of “ordinary residence”. An overseas visitor is any person who is not “ordinarily resident” in the UK. A person will be “ordinarily resident” in the UK when that residence is lawful, adopted voluntary, and for settled purposes as part of the regular order of their life for the time being, whether of short or long duration."