8 turns.
If I get the Great Artist I need, and my three Legendary cities can survive the next 8 turns, I win. That is the deadline for the others, all of whom (except DZ) have declared war on me, although, as is becoming typical, neither wetbandit nor JR4 has attacked yet.
Wetbandit
Wetbandit remains my primary concern, if he advances with his whole force next turn, it'll be very problematic. Fortunately, he might be planning to go a different direction than just straight in, which would give me some more time.
He's railroading DZ's land and might be staging Tanks for an attack on Athens. Those 4 aren't enough, and his main stack can't actually reach Athens from there in a single move (if my recently improved knowledge of railroad mechanics is holding up). I moved a single AT into the city, the plan being to require him to commit more than he'd like to to take it. I really wish I had about 30 more ATs now. They're like Rifles against Cavs, load up cities with them and it becomes too costly to just charge in with the fast-movers. That's at the core of my current plans regarding JR4, and to a lesser extent, SD.
If wetbandit instead just stacks everything together and moves in towards my main cities, one tile at a time, I'll probably have to retreat before him, putting enough in the cities his Tanks can reach to prevent him to burning them with just a few units, but inevitably surrendering the cities, until such time as I am forced to hit it with all my stuff. I can kill that stack, but I would probably end up losing most of my Artillery, which would make it hard to deal with follow-up stacks from SD or JR4.
JR4
JR4 is the least threatening, although his Fighters have the potential to be really problematic vs my Airships. They are deadly against Airships. Unlike MGs, ATs, or Destroyers, they can intercept multiple times in a turn, and their intercept probability is 100%, and only goes down as their health goes down, and Airships have such low health they won't do much damage to the Fighters as they get intercepted. They basically completely negate the Airships
His problem is his stack, such as it is, will instantly die if he attacks. He has a lot of Tanks, but not nearly as many MGs or Infantry ready to defend the stack as wetbandit. A lot of his MGs and Infantry are tied up garrisoning his coastal cities against a naval attack by me.
So as long as he's scared of that, he can't really advance. My garrison in Yee Hawdists is there to make any attack by his Tanks too costly, each of my units there should kill a Tank on defense, mainly thanks to the 80% cultural defenses. And hopefully, some of the ATs would kill more than one. He'd take the city if he does do that, but I'd be happy for that to happen, since he would lose enough Tanks that I'd not really have to fear what remains as much. If he advances slowly, I'd retreat from the city, since he can move next to it from his own territory. But after that, he'd have a lot more of my culture to wade through, and at some point I'd kill his stack, with a lot less losses than killing wetbandit's would take.
So far this game JR4 has been very cautious, not jumping in on the earlier wetbandit dogpile, and not conquering even more of DZ's land after he basically destroyed most of DZ's power, especially his Artillery. He's the one most likely to care more about his position
after I'm defeated, and therefore the least likely to commit to stopping me. So I hope he doesn't realise how close I am to winning, and delays and hesitates until it's too late.
Superdeath
Nothing much has changed here since last time I reported on him. His main stack of Transports can still only hit Vanillaisis, so I was able to withdraw units from Talibangelical this turn.
He has moved a small force up to the north:

That X markes where he'd have to be to hit my Moai city with them. But it's still only 3 Transports, so I wont need to divert that many units to defend it. Wetbandit's navy of a decent number of Battleships and Destroyers is also up there, I can only hope he doesn't move it all the way down to join with SD's.
But otherwise, things haven't changed here, he still doesn't have the numbers to take Vanillaisis.
Here's the sum total of my military:
I did delete all my Frigate this turn, they were less than useful at this point, too weak to cause much damage and seriously lacking in range. And I need as much money as possible.
On to the timeline. The 8 turns comes from this city:
I did a lot of math, and I calculated that if, starting next turn, I turn everyone into Artists, with the exception of the Town, I'd reach over 46000 in 8 turn. Then all it'll take is one GA to make it go Legendary. The advantage of this is that if I don't get the GA out of Yokel Haram I hope to get, I'll have another chance of one here.
My capital, which has the least amount of Culture right now, will need 2 GAs to get to Legendary, or 1 and a few more turns:

So even if I don't get a third GA from either city, it'll only delay me by a couple of turns. Also, an even 1000 culture/turn is awesome.

The turn before it'll starve down I'll turn everyone into an Artist, so it should generate the GP in 7 turns (I think, I haven't done the math here, if not 7, then 8 turns, which will be enough).
So, 8 turns. Can I survive for 8 turns? Well, not if everyone attacks all at once. But they haven't done so yet, so hopefully, by the time they do, if they do, it'll be too late. In an ideal world, every one of them sits around waiting for another to attack first for the next 8 turns.
The only problem with that is Superdeaths, who, if he wants to, can figure out my exact culture plan entirely, thanks to his city-vision, and guess when I plan to win a lot better than the others. So if the others do nothing for the next 6 or 7 turns, and he realises I'm only a turn or two from winning, will he sacrifice everything to try stop me? Knowing if he succeeds he's in a worse position afterwards compared to JR4 and Wetbandit? If I had to guess what SD is going to do if he thinks his chances to win are lost, I'd think he'd do something as spectacular as possible, against someone he thinks deserves it. I don't know who that is most likely to be though.
However, I'd be willing to be he's been complaining in his thread about JR4 and wetbandit's reluctance to actually attack me, and would rather me win than help one of those two do-nothings win. I could be completely wrong on all of that, but I've played a lot of games with SD, and that's my current read on him as a player.