So I made overnight steel-cut oats, and they're okay. Now I'm not exactly an oatmeal connoisseur, so I'm probably a shitty person to review them. That said, I'm okay with them! (And that's pretty much all I'll ever be with oats.)
I followed this method because the double-boiler appealed to me. I used 1 cup of the steel-cut oats, 2 cups of water, 2 cups of 1% milk and a pinch of salt in a glass bowl. I stirred it up and set the glass bowl in the slow-cooker (technically a Crock Pot!) and poured in enough water so that the level of oats matched the level of the water. I set the Crock Pot on low around 10 pm and ate a portion about 7:15 am (with a splash of milk, a little Splenda and some cinnamon -- nothing else, toppings are weird).
Next time I'll half the recipe because I don't like to eat the same thing every day, and this made a ton of oats. But I'm pleased. SO MUCH EASIER than the stove-top (or using the microwave and dealing with the overflow that ALWAYS happens).