There is juicy land to the East... (That Clams, Fish, Wheat might make a nice Globe Theater if we can settle that far away in time...)
Wow, ambitious. (I've said that about bcool's ideas before!) We'd have to arrange two galleys carrying settler, worker and two defensive units, and trireme escort, and preferably a workboat or two. It'd have to build lighthouse, granary, courthouse, barracks, theatre, GT by about T230-250. It'd cost quite a bit to support, but we'd be generating our draft units close to what might prove to be the/a sphere of action. Much will depend on what we find out about Lizzy's continent and the one in question.
I think we should put an exploring trireme (or maybe workboat) to go north around Lizzy's continent on the drawing board.
Detailed thoughts about such a GT city
I'd settle 1N of fish. Note that the wheat has fresh water from an inland lake 1NE, so three of the grassland tiles around this site can be farmed, so at size 6 we work fish+clams+wheat+3farms for a

excess of 15, which is one larger than even CC can ever do. There's a Ghill in the fog, and I think another plains and grassland.
Assuming Maths+Caste+Guilds but not Music, infinite

and happy at size 9, sending trireme, 2 workboats and 2 galleys with settler, worker and two defensive units I can spreadsheet-build LH, granary, CH, barracks, theatre, GT in 70 turns. This doesn't build the wheat farm until late, and does spend time running citizens before workshops get built.
If I send two workers, then there's time for the wheat farm and faster growth to 9 and GT in 54 turns. The workers have had time to workshop both plains and all four grassland, and start replacing those with farms for the drafting phase. A third worker would only make this a few turns faster, I expect.
Both of those would be faster if I skipped the barracks and built it after the drafting starts. A forge at 180

would pay back its hammers in 36 turns (25% of 21

sustainable at size 8). That might work in the one-worker case, but is too slow in the two-worker case.
Travelling takes 14.5 galley turns from outside FH, so we found 16 turns after departure. We'd have to send a scout earlier - lone galley with archer and worker? (Dump the passengers off if we spot a barb galley.) So to make this plan work (sending two workers) by T230, the site needs to be free at T176 and we have to set off by T160 with at least galley+trireme+settler+worker, having already sent galley+worker+warrior, and something to scout Vicky's island from the north. Two workboats have to get there one way or another. We'd have to follow up with more defenders.
We should WorldBuilder how much that city will cost to maintain.
We can do all the above, but it will slow down the local settling. Is all this worth it, in order to keep CC teching and FH working as a

-pump efficiently during the drafting phase?
I think it might be worth it. If that land mass does not have an AI on it, then we probably only have to race Vicky, and she has a bunch of land on her own landmass to settle. (Will she settle off-island before her island is full?) If she does settle her island fast, we might be able to use her roads. She'll also be fogbusting, so we might get away with not sending a trireme escort, or having a north-scouting workboat hide in London until useful. We'd have to scout Vicky from the north ASAP to be able to make the relevant decisions in time.