Cold blanket through the balcony - experiences?

Hello everyone,
this concerns the same room (living room) that I had already mentioned here some time ago in with a slightly different problem.
Back then it was about the constantly fogged-up panes on the sliding door. Over time it has become clear that the moisture does not only settle there, but also on the ceiling above. This causes mold to repeatedly form here, along the entire edge of the ceiling – no matter how often the mold is removed.
Recently, when the temperatures dropped below 0 again, the temperature of the ceiling in the middle was about 19°C, at the edge about 5°C! You could directly see the droplets forming there.
One additional fact that I had never paid attention to: Above this side of the room there is a balcony. I only became aware of this when I recently looked at the building plan. (Picture attached: the room on the upper floor with balcony, the size of the room below with the mold problem marked with red dashed lines.)
I suspect that the fact that at this edge there is a balcony (18 cm concrete slab) instead of heated living space above significantly contributes to the area being so cold that the ceiling becomes like a dripstone cave.
How can this condition be improved? Here are my own thoughts with a request to comment on how sensible my considerations are:
1. Insulation of the balcony above + new floor covering. Problems: Only limited possible build-up height due to the low threshold of the balcony door. Also, the apartment is currently rented out.
2. Insulation of the ceiling on the ground floor, where the balcony is above. Problems: Should one insulate on the "warm" side? Insulate the entire ceiling, although only about 1 m at the edge is necessary? Or insulate only 1 m wide and build a boxed-in area around it, with built-in lighting, so that it looks as if it’s supposed to be that way ;-)
3. Combination of 1 and 2?
Thanks in advance to all commenters.

1A thermal bridge with additional cooling fin function. Cantilevered concrete slab and additionally exposed at the top. There are different options - descending order in efficiency: The goal is always to either completely obstruct the path of heat flow (fully wrap it) or to make it as long as possible.

1. Remove/cut off the balcony and insulate the remaining concrete slab at the front and top sides.

2. Insulate the balcony on all sides. On the top side, 2 cm XPS, reinforcement, and tiles are sufficient if necessary, resulting in a 4 cm build-up height. The front is difficult to insulate due to its shape.

3. Insulate the balcony top and bottom and leave the front side exposed; flank insulation already weakens the effect. Only the bottom outside has almost no effect.

4. Insulate only on the inside. The width of the overhang plus 1.5 m is sufficient; more does not significantly improve the effect. Insulating concrete from the inside is critical because any moisture behind it practically cannot escape anymore. Therefore, this is the least helpful and the most critical solution in terms of building physics.

If the balcony is to remain, I would recommend at least option 3, preferably option 2.

Thank you for the contribution.
Tearing down the balcony is out of the question, as the apartment is, as mentioned, rented and I cannot/will not simply take away the balcony.
Oh, I should have mentioned: The shape of the balcony is (fortunately) not as on the construction plan, it is just a normal rectangle.

I hadn't really considered complete all-around insulation of the balcony.
Is the effect really that big if you insulate underneath and additionally the front? Can this be quantified? Are aluminum-coated PIR/PUR boards suitable for this, which I still have left from the basement ceiling insulation?
A 4cm build-up on top will be difficult, since the balcony door has a very low threshold, I think it’s hardly possible to scrape together 2cm...

it's about the same room (living room) that I mentioned here some time ago in with a somewhat different problem.

Why have a balcony at all? - the linked location looks like a ground floor unit (???)

I may have described that ambiguously. The picture in the linked thread is of the room that has the mold problem on the cold ceiling. This is located on the ground floor. The room on the floor above is smaller, presumably to be able to create a larger balcony (see Bauplan). This balcony therefore extends a good way over the mentioned ground floor room and is the cause of the cold, damp ceiling below.