10mil human eggs or embryos or just genetic material but with bio substrates to print from seems likely to survive a 500 year long deep space journey and far more achieve-able based on current tech.
Send a probe to seed a planet with bacteria etc. Send another to arrive a few 100 years later to seed it with plant life. Work your way up. The last probe arrives and starts printing\gestating humans and offering them educational videos and a safe-ish environment...