I feel as though the questions who, what, where, how, why and does still truly apply. We don't know if life exists elsewhere. There are clues pointing in this direction, sure, but until physical life forms are identified, then these questions are still very much fair game. However, I do feel as though the 'where' question is of the most significance importance when it comes to existence of life, as you mention.

Where do we look? More accurately, where can we look?