Not many people live in such regions. And building enough solar and wind for the billions of people who do live in the good locations for it will drastically reduce the price of energy due to scale.
This will effectively render the issue moot, the few people in those regions could burn fossils and it wouldn't really matter. But it would be cheaper for them to import green energy.
There are not enough of them to be a big problem. Numbers matter.
They are importing fuel now, and may continue. In the future the fuel they import will be cheaper if synthetic. Or they may rely more on transmission lines, and stockpile synthetic fuel for backup in case of outages.
People everywhere will do what works best for them where they are. As synthetic fuel cost drops below extracted and refined hydrocarbons, people will simply stop buying the latter. Forward-looking sunny tropical countries will do well exporting synthetic fuel to places where the wind or sun flags.
Anhydrous ammonia stores liquid at room temperature under light pressure, stores energy per unit volume close to hydrocarbons, and can be burned where they can.
But in the near future, synthetic methane will be cheaper than mined natural gas. More expensive than ammonia, necessarily, because it needs carbon.
They can ship in synthetic ammonia from the tropics to burn, as they do oil and gas now, or get power via transmission lines and synthesize and bank it locally; or some of both.
This will effectively render the issue moot, the few people in those regions could burn fossils and it wouldn't really matter. But it would be cheaper for them to import green energy.