When I first started BNW, I started on Prince, beat one game easily, moved up to King, beat one game easily and then moved to Emperor. I stumbled at first, then had one game where I won by a knife's edge in a space race with another AI. Then managed to beat the game using liberty starts and even winning a CV as Germany with autocracy ideology.
At that point, I moved to immortal and it sure is hard to win. I've only won 4 games on immortal and one of them only contained 6 other civs, one of them being the Zulus who annihilated 3 other civs which made my cultural victory really easy. If I continue playing, I'll still be stuck on Immortal for a while, even if I try to get NC earlier or beeline to education. I really don't know how you can pull off a CV with a larger number of civs, because most AI aim for a cultural victory.
By the time I even think of moving up to deity, civilization beyond earth will be released by then.