Final update before the game is over:
It's now 1350 AD, just passed the 100K level with about 1500cpt (total 225 cities with 37 settlers). I've begun setting new builds to wealth as with only about 16 turns to go, I see no other viable build for remote cities. I just lost the race to Sistine Chapel, which is the final stray in dealing with Lizzie. I've created her a little gulag on a 6 tile island (1 mountain & 3 marshland), that I just gifted her. I'll be giving attack orders to my knights next turn. All cities except London & York will be razed, so I'll have to abandon 3-4 of my current cities to keep Sistine, GLit & Colossus.
In the last 15 turns I managed to improve my finish by 3 turns and with luck I'll be able to cut 1 to 2 more off it. At this point however, there's not really enough turns left to radically improve the finish. I've thought about getting 4 turns from the finish and signing peace with England and getting Education to see how much culture I'd be able to recover from the lost temples by pop-rushing replacement temples & universities. I also switched my Sistine pre-build to a palace, so making it to Music Theory would mean an instant Bach's Cathedral.
One note of interest. I checked with my military advisor, who says to build more knights. I've got 60 plus 15 AC & 3 Crusader Armies, which is well beyond what England has. I'm also able to support over 1000 units.