You basically have it with the hardtop on.
You either like convertible tops or you don't. It sounds like you don't. Since the miata single-handedly brought back the roadster market, it is obvious that many, many people do like it. Mazda is probably being smart by leaving it a roadster only and not even offering a coupe version.
This is by far the worst time of the year to drive top-down where I live, except at night when it drops down to 75 degrees. I don't have any periods as long as a week, much less a month, where I have to deal with snow and ice.
I assure you that a miata has been my only car for about 7 years now. Before that, I drove 2 seater Z-cars for a good number of years.
Out of almost 22 years of driving, a two-seater has been my only vehicle for at least 16 years of that time. Being able to carry only one person has been a blessing for me far more often than it has been a problem.
Pat