It's not really a new insight that planetary bodies outside the "habitable zone" can have large bodies of liquid water. The moon Europa, orbiting Jupiter, is known to have an ice-covered ocean for quite a while now. The reason for the liquid water are graviational effects, kind of like squashing a tennis ball. But there are many other reasons such a body might be warm enough for water to be liquid.

Anyway, contemplating extremophiles (lifeforms, mostly bacteria, that thrive in extreme conditions), I personally think some forms of life might not even need liquid water. Then again, this is all speculation.

It's incredibly unlikely that we're alone in the universe. That makes it more interesting why we haven't found any extraterrestial life yet.