Water is neded so the penguins wouldnt have much of a choice. Huddling together can keep them warm but eating fish to gain blubber is good because rhey stay warm in the cold with extra fat. Getting cold for a little to get fish is worth warmeth from the other penguins and satisfaction of hunger
Water is a cold element, so penguins needed to huddle with other penguins to be warm from the blizzard( known as to cover with other penguins to stay warm)