Realize that if the cosmological constant has the nonzero value that appears to be the case (in the lambda-CDM model), then only about 6% of the galaxies we see are still reachable. The rest will be carried away by accelerating expansion so quickly that a photon emitted from us right now (or any slower than light spaceship) will never reach them.

Of course more stars increases the chance of life out there, but without a good handle on the chance of life arising around a random star, we cannot set any lower bound on the probability that life is out there on the stars we see.