What if fish were immune to winter?

Right now, fish RGO's suck major donkey balls, nobody likes them, you use them basically as designated city spots, because they're the worst resource and you're willing to sacrifice them for cities...

BUT! What if the penalties you get for winter (and mini-ice age) did not apply to fish provinces? It could actually make it worth using them a bit more in certain regions, especially colder climate regions that historically did in fact rely on fishing a lot.