The “habitable zone” for a planet orbiting a red dwarf may be closer than Mercury is to our sun. And like Mercury the planet’s rotation around its axis would likely be phase-locked to its orbit, leaving one side in continual darkness and the other side in continual sunlight, blasted by red dwarf flares.
These factors and many others suggest that, with all the planets associated with the billions of stars in the Milky Way galaxy, the estimated probable number of planets with Earth-like conditions hospitable to intelligent life is likely very close to the experimentally known value of one.
I agree with you. I think that in the hundreds of billions of galaxies in the visible universe, that the average number of planets with a fully developed intelligent species such as ours (yes, I know, we have muslims and democrats, but even still, I think we qualify) is 1 per galaxy.
That’s my guess.
This assumption, if I'm not mistaken, implies that in an infinite universe of galaxies, each having a Gazillion stars, with every star having a 1 in a Gazillion chance of harboring life, 1/e of all galaxies will have no life, and likewise 1/e galaxies will have 1 star harboring life, with the remainder having 2 or more stars harboring life, including 3 in 1000 having 5 such stars, and 1 in 10000 having 7 ... all based on the Poisson distribution.