Could there be life in the inner solar system? well, I don’t see why not. We have found life that lives up to 3000 underground, we have found life in the ocean at insane pressures and intense heat, and now this new life that basically lives in poison. It looks like life can live more or less anywhere, so the conditions for life are probably not as strict as we thought. However, I suspect life is much like a virus, once a planet is infected, the life covers all of it. With that in mind, I suspect the amount of planets that have life is the key point.
If we say 1 in 10 of all planets develop a form of life, then the odds are that we are the planet with life in our solar system. If the odds are even more against us, then we may find not many planets have life, but the ones that do are covered in it.
Personally, I would not find it unreasonable at all, that any other planet in our solar system has life. But as I’m a bit of a skeptic, I’m still going to air on the side of caution, and say the life in this planet is probably it for this solar system.