Service stations can be 300 km apart because this seems to be an acceptable distance with gas powered cars. If there is a demand for service stations every 150km, wouldn't you think they would be built?

The remote regions you describe, currently powered by diesel generators (where does that fuel come from?), isn't there an incentive to power them by solar and also charge electric cars that way?

And even if there are some remote spots on earth where electric cars are not useful, how large is the market share for cars for these regions? If Toyota continues to make land cruisers for those regions, what does it matter for eletrifying 99% of all other cars?