re: health insurance coverage in the private sector
What you are describing is supplementary Medicare insurance, essentially an appendage to Medicare.
It is now no more possible to reject Medicare and go with a totally private insurance solution than it is to reject the Social Security program for a totally private retirement solution. To the best of my knowledge, no such policies exist any more.
And of course, the Democrats won't rest until the last, squirming bit of the private health industry has been ground underfoot.