Perhaps you've heard of Winter's Gem, and of the tragic fate of the Lady Karina. And perhaps not. It is, after all, a tale unspeakably old. Yet the Earth does not forget, and those of us who guard it do not wither...
Nine thousand years she has slumbered, while Winter diminished. So obsessed was He in her care, that He allowed Summer to run unchecked. His power dwindled, and Summer grew. There is a great unbalance in the world, young ones. One that I fear will break the back of the Earth itself, if not addressed. Winter must return. It is the Way.
A real-world location fit for filling out your adventure; where norse icelandic fishermen suffered unthinkable conditions throughout frigid winters to harvest the fruits of the ocean.
In the summer there is a small stone jail for those who are caught breaking the rules of the Sorcery Springs Geyser Basin, but in winter they are imprisoned within the warm waters themselves. No bolts or bars are needed, the cold takes the place of prison walls.
For those familiar with cantrips, you know they are minor acts of magic that have hardly any noticable effect on the world. For example a cantrip to make your food taste better won't heal you any more, or be any more nourishing, just won't make it so hard to get it down. A light cantrip certainly won't be able to blind or even distract anybody, but you might be able flash it to signal someone looking at the right spot.
What if children's nusery ryhmes were a form of cantrip? Like the "Rain, Rain, go away, come again another day." One child singing it wouldn't do more than spare her house a couple raindrops, but what if the whole village got together and was chanting in unison? Each one doing just a bit might actually be able to divert a whole storm...