Would you take the option to survive but live in bondage, or would you remain free with a one fifth chance of survival?

Imagine a humongous asteroid is detected on collision course with Earth. At the rate which it is closing even if the people of Earth could mount a defense it would be ad hoc with only a 12–15% chance of success in saving the planet. When the planet is struck three fifths of the population will be wiped out. Of the two fifths left, half of them are not expected to survive the severe climate changes and food shortages. When mankind looks all but doomed, extraterrestrials show up with a plan; for those who wish (they would never be forced to take it) they will be evacuated to the planet of the extraterrestrials but will have to live as slaves or servants, 5th class citizens at best, but they will survive. The extraterrestrials have observed mankind for centuries and do not want the cancer or mankind, hatred, greed, war, planetary exploitation, etc. to infect their society so any humans taking evacuation will be kelp on the shortest of leashes. Those not taking the offer will be left to take their chances and fend for themselves, once gone the extraterrestrials are never coming back; there is one evacuation, one time. Which option would you take, knowing you would survive but not be free, or know you are free with a one fifth chance of survival?