It has always intrigued me that we consider the possibility of other life forms in a manner that is largely relative to our understanding of life on earth and, hence, biology. But, even our understanding of DNA need not be applicable to other life forms.
I don't see why there has to be any real limitation on conditions or otherwise. As the article mentions, we have been surprised to find extremophiles near thermal vents right here on Earth (which reach temperatures roughly equivalent to the Venusian surface). There we find, for instance, bacteria that rely upon hydrogen sulfide vs sunlight for energy. This is what we consider a "harsh" environment of chemicals, heat, pressure, etc. However, when we attempt to remove organisms from that environment to study them, they usually die pretty quickly. In other words, ours is the harsh environment as far as they are concerned.
Elsewhere, we have found organisms whose DNA was thought to be composed of arsenic vs phosphorous. While this was ultimately refuted, for a period we once again thought we'd discovered something that, in an instant, completely changed our understanding of life.
So, I guess my point is that we assume life must conform to certain requirements and/or conditions until we find life forms that violate our assumptions. Given a Universe as vast and diverse as our own, I sincerely believe that anything is possible and perhaps even likely.