Settled 1N as I figured I wouldn't be able to work the entire BFC anyway and maybe I could culture flip something with a city by the lake.
Early techpath AH->Pot->Wri->BW->Monarchy->CoL->(bulb math)->Oracle CS. BW was probably unnecessary that early.
A few turns later I met the first AI.
Next up was Great Library, then I saw Vicky settling a city 3 tiles south of the lake, so I went music next and settled and culture bombed my 2nd city, hoping to culture flip Nottingham. It looked good at first, I quickly got up to 30% culture on the city tile. But then it stagnated. I basically wasted my 2nd city entirely on this effort, building library, monastery and stele, then culture for a long time, but it didn't help. Even after I got the 4th border pop at 5000 culture I couldn't get more than 30% on the city tile in Nottingham. It never flipped.
I should have waited with settling the city until she had cleared the jungle and improved pigs south of lake. I could have easily stolen that tile and this would have made the city a lot better.
Libbed Physics, could have been a lot earlier here if I had done something more useful in 2nd city than building culture and used the GA from music on a Golden Age instead of the worthless culture bomb...
By this time it was clear than being first to Mass Media and building UN is no problem, but getting the votes is.
Shaka was crushing Asoka, despite Asoka having longbows, maces, knights and pikes while Shaka had nothing better than pults and phants. I feared Asoka vassalling to Shaka, so I started gifting him airships. After giving him 6-7 airships, he managed to take one of his cities back (he had lost his core by this time) and eventually made peace. It was looking good, as it appeared I would run against Shaka in the elections and getting the other votes was easy. But then they went to war again and this time Asoka bribed in Hatty. Hatty quickly took a few cities of Shaka to become the largest civ on the map and I knew UN was pretty much a lost cause. I still got elected secretary general, but before the first vote, Mansa peace vassalled to Hatty and the game was definitely over. Getting Shaka's votes without getting -4 "you traded with our worst enemy" with the rest of the world would be impossible.
The map is for sure winnable, but you need some luck with how the diplo situation develops, in case you are going for UN win. There's not much you can do to influence it early in the game. I didn't meet Shaka until a few turns before getting Physics, otherwise I might have bribed the whole world on him for the shared war bonus. But by the time I met him, he was too big and the world feared his military might.
Flipping a city south of the lake might be possible. Maybe if you go caste and produce another Great Artist for another culture bomb. If you manage to flip a city, that would really help a lot. After that anything would be possible.
I'm now thinking that settle 1NE and building 3 cities is best. With trade routes the extra city is a net gain no matter how bad it is.