I hit 100k in 1752, but didn't reach twice the culture of the Iroquois until 1762.
My plan was to expand, head for republic, research at max to railroads and communism, and then pop-rush like crazy. Overall I was pleased with how it went. I wasn't ready to take on the Iroquois when I needed to, but at least I noticed the MPP and waited it out before declaring, so the war went okay once it started. The Mongols and Koreans protected me nicely, but weren't much help taking cities.
Sistine Chapel was nice for my towns that got cathedrals, but 160 shields isn't easy to get by pop-rushing. 100k isn't very speedy when no cultural buildings are cheap.
Switching to communism crashed my economy, but I was prepared for it. I hadn't thought about this meaning the lux slider was useless, but I hadn't planned to use it anyway, because I knew I'd have no money. For a while I was selling my maps after every tile improvement, though. The Iroquois paid me a lot of money, but once I had to declare on them my financial situation was pretty poor. By the end of the game, each of corruption and maintenance was costing nearly 3/4 of my income from cities.
Notes:
Settle in place, worker to wine, CB at max, start a warriorx3
Hut to south gives warriors
CB to BW
3100 meet Babylon
2800 meet Mongols, new settler goes toward cows on lake
2630 meet Carthage, settle Veii next turn
2030 meet England
1990 learn iron working, trade for many techs
hut to east is empty
1790 settle by iron
1700 trade for all contacts, many techs
900 trade lit for techs and workers
630 refuse a demand from Mongols as they are pretty far away, they declare
410 learn republic, revolt, 4 turn anarchy, see barb hordes.
330 become a republic, start golden age when Korea attacks
Take out Babylon, most of England, some of Carthage
Mongols attack
1255 anarchy ends from revolt to communism
1555 Carthage is down to one far-away city. Waiting for Iroquois MPP with Korea to expire so I can attack Iroquois safely with allies to eliminate Iroquois culture threat. (Currently 49208 + 949 per turn for me, 39070 + ~463 per turn for them). Iroquois have been paying me big money, so this will cause financial woes for me.
1635 Selling maps after each tile improvement is keeping me afloat, 11 turns in to war with Iroquois. Now at 66k, 1182 per turn. Iroquois at 45781 + 387 per turn, still with 25 cities.
1752 Hit 100k, gaining 1654 per turn. Still a bit more to make 2x Iroquois, now at 53k + ~200 per turn.
1762 Win with 109204 culture, 1741 per turn, and 191 towns. Iroquois down to 9 cities, MapStat says 54011 culture.