It's believable that a technologically advanced society can cross a galaxy by star hopping and colonization of successive planets, maybe even without generation ships or cryopreservation. E.g. after taking into account relativistic effects, constant acceleration/deceleration at 1g gets us from Earth to Alpha Centauri and back well within a human lifetime. But you can't star hop between galaxies. There's nowhere to pick up supplies aside from maybe hydrogen and helium. Even at full lightspeed you need ships that are capable of running for 100,000 years to reach even the nearest galaxy. Is it feasible to build a fire-and-forget colony ship that could survive 10E5 years in space and arrive in working shape? Maybe if you did it with some really robust panspermia or something, and were willing to lose 99% of the the ships you sent out. I.e. just maybe you could transmit biology, but I very much doubt intergalactic civilization is feasible.