To be cynical, a lot of things are possible. It's possible that anaerobic bacteria still live in small pockets beneath the surface of Mars. It's possible, if unlikely, that extremophiles survive on the sweltering surface of Venus, or floating in its sulphurous clouds. Of course, the fact that these things are possible is still incredibly cool. While this article lacks much technical substance, this is the kind of thi…
Floating in the clouds of Venus, sure. There's some semi-Earthlike zones in the cloud layer. On the surface, very probably not. It is unlikely that there is any structure that could pump entropy out of the cell faster than the horrific surface environment of Venus would be pumping it in. (More conventionally known as heat, but I find this formulation helps focus on the fact that "too hot" really is an intrinsic problem for life, not merely an incidental one that might be overcome by more chemistry.) I'm not even 100% convinced that a technological solution is possible that could work over geologic time frames, let alone adding the restrictions of abiogenesis on to the structure. (Though on the topic of abiogenesis, it's difficult to see how to apply any of the current thoughts on that to an atmospheric environment; Venusian extremophiles would also probably be immigrants from Earth.)