I read this novel in the 90s. The main character goes into cryonic suspension several times. In one era the planet is dying. Humans are struggling to survive. There are very few humans, life is grim and they live underground. He freezes again, and millennia later humans live in space stations above earth. He is sort of a concubine for a female leader. They also have genetically modified gorillas as servants. At each of the times he always somehow reunites with his girlfriend who has also frozen and reawakened. She's a redhead.
It'd be amazing if someone can ID this novel.