Would building that North-South transfer capacity even help? It seems like the basic mental model here is that it would equalize prices between Northern Sweden

Would building that North-South transfer capacity even help? It seems like the basic mental model here is that it would equalize prices between Northern Sweden and Germany, not between Northern and Southern Sweden. And Germany is quite a bit bigger than Northern Sweden. So what should then happen during these German shortfalls is to move the German prices (and Southern Swedish prices) down by an imperceptible amount, while the Northern Swedish prices go up by a ton.