The 3 needs for life are met already in Antarctica. You have animals for food, plenty of water, and can make shelter. The problem with it is that it isn't comfortable and the shelter is bland or difficult to get right.
So in my Antarctica, a new sapient species lives there who have natural talents in shaping ice and moving through snow and water. They have both gills and a normal respiratory track, so that they can live in both environments.
There are two races that have evolved from what their ancestry have done. Those that tended to swim in the water to hunt fish and grow underwater crops are called the Pingins. They have more developed gills and are slimmer, with their skin being more resistant and colorful. Pingins tend to be playful and energetic in nature as they tend to communicate through their actions. The ones who have hunted animals through the snow and air are called Polrbers, with the middle R being silent. They have more developed lungs and are a little thicker because they have more insulating fat and their skin is a shiny white to look like the ice around them. They tend to be quite and reserved and speak with precision.
They have built cities in the form of spires that are masterfully designed to weaken the weather that blows through them. From a distance these look like intricately decorated icicles that jut from the from the ice. These can be found pointed up into the air and down into the sea. In the water they have designed plants that can survive the cold temperatures and have farms being their main industry as they make most of the food and theater their main entertainment. The air portions are where the industry part is as they make most of the tools that tools that both races use and art is their main entertainment, especially landscape scenes.