Fargo, ND has approximately 14 ophthalmologists and 100,000 population.
El Paso, TX has approxmately 30 ophthalmologists and my guess is that there are 1M people there.
Anchorage, AK has approximately 16 ophthalmologists and covers half of the state, but not Fairbanks.
Wichita, KS has fewer than 20 ophthalmologists but not 1M population.
Rapid City, SD, near Mt. Rushmore, has approximately 10 ophthalmologists, and possibly just 2 retina, no cornea/glaucoma/oculoplastics/peds. Not 1M people but half of the state and a bit of Wyoming.
Fargo is colder than Anchorage. Anchorage has beautiful mountains. You could do ok in all 5 cities. Anchorage might only have 2 retina, 1 neuro, 1 peds, 1 glaucoma, so there may be extra work. Of the 5, Anchorage seems to have the best lifestyle, Rapid City has few subspecialists, all probably have enough work for a new person.