Kitchen element on exterior wall. Distance or internal insulation?

Hello,

I hope you can help me with my problem.

Our kitchen is just over three meters long on the left and right and ends with a unit on the exterior wall on each side. The exterior wall is on the north side, and we previously had mold between the refrigerator and the exterior wall + the sink cabinet and the exterior wall.
The problem was solved in the then 20-year-old kitchen as follows:
Refrigerator moved from 5 cm to 15 cm away from the wall
Wooden board of the sink base cabinet on the exterior wall side "cut out."

Now the kitchen is to be renewed. The refrigerator will remain as it is, but my wife envisions installing the sink base cabinet with only 5 cm distance to the exterior wall (since this cabinet has an "interior," we cannot cut it :-)
To make matters worse, the 5 cm gap is also to be covered with a front panel (see picture).

Question(s):
- Can the cold exterior wall be prepared with internal insulation in such a way that the sink base cabinet can safely be placed so close to the wall?
- Should the sink base cabinet possibly be reduced from 60 to 45 cm, so that there is about 18 cm distance between the exterior wall and the cabinet and the air can circulate better? Would a front panel then be counterproductive?

I would be very grateful for tips!

Regards
Tobias

I would have no concerns with the small area. Ideally, there is also underfloor heating beneath it.

What would be appropriate for insulation? Would painting with silicate paint possibly suffice? Thank you Tobias

There is nothing wrong with interior insulation. We also have bonded panels with 3 cm Styrofoam on all walls in the solid construction below (it was already like that), nowhere any mold, even though the house was empty for 1 year and the lower floor has not been heated for at least 8 years.

It is important to install the interior insulation in such a way that it cannot be bypassed under any circumstances, and the surface should also be vapor-tight. Otherwise, the moist indoor air would condense on the cold wall behind it. For uneven walls, one should use soft insulation, as it fits more tightly (without gaps). For completely straight walls, one can also use rigid panels like Styrofoam and fully glue them over the entire surface. The dowels should of course be correspondingly longer.
In the upper floor (timber construction), we have also installed interior insulation on all exterior walls, but there with battens and wood fiber boards plus climate membrane and then double cladded (OSB, gypsum fiberboard).
These are two examples of how it could be done.