Thermodynamics still limits what you can compute and, given the output of a single star, you're still limited in what can be computed.
But I think it's a mistake to try to characterize any civilization by a single motivation. People on Earth do things for many different reasons and I think we should expect the same of alien civilizations even if single motivations tax our imaginations less. The questions is if any of the motivations driving a stellar civilization would be enough to prompt the establishment of colonies. I don't think you can say that the answer will be 'no' reliably for every civilization that might arise and it only takes on to colonize a galaxy in short order (by cosmic standards). Hence sophisticated life is probably very rare.
But I think it's a mistake to try to characterize any civilization by a single motivation. People on Earth do things for many different reasons and I think we should expect the same of alien civilizations even if single motivations tax our imaginations less. The questions is if any of the motivations driving a stellar civilization would be enough to prompt the establishment of colonies. I don't think you can say that the answer will be 'no' reliably for every civilization that might arise and it only takes on to colonize a galaxy in short order (by cosmic standards). Hence sophisticated life is probably very rare.