Condensation: extra vent?

[Aunt Angus]

The "cornice" vents would keep things dark, I would think.

 

[Chicken crossing the road]

Yes that is what I meant, either square vent like you have on the gable ends or if you can get them? then I would use the round ones that just require you to drill a hole ( I like easy). You could do more then one depending on the size you find, I can get 1” 2” or 3” etc.
spread them out.

As aart pointed out you don’t have a soffit/ cornice so you will have to put them high on the wall just under the overhang.