There is no reason to believe that intelligence, in whatever form it takes, ever stops being energetically expensive. Is it possible to imagine selection pressures that would select for high intelligence over other factors? How harsh can an environment get, or how easy, before something like brute strength or rapidly breeding is always a cheaper strategy?
Some rules are universal, because they're thermodynamic. That's not to say that your species of intelligent individuals is impossible, but it is unlikely. When you really take the time to think through these scenarios, you often find that there is no justification to assume that exceptional intelligence would evolve.
We already know that thermodynamics and evolutionary pressures can allow for intelligent beings with a population average IQ of 100 (on the arbitrary scale we've devised for ourselves) to exist, since we humans do exist. I'm suggesting that a slight increase in that population average might be enough to make a large difference in how we collectively respond to mid- to long-term problems.
If you're arguing against that suggestion, it seems you would have to be arguing that human intelligence exists at a level that is nestled directly up against some kind of hard thermodynamic limit, even though a non-trivial portion of our species already exists on the other side of that line. I don't see how that argument could plausibly be made.
Some rules are universal, because they're thermodynamic. That's not to say that your species of intelligent individuals is impossible, but it is unlikely. When you really take the time to think through these scenarios, you often find that there is no justification to assume that exceptional intelligence would evolve.