Floor plan approximately 200 sqm (3 children's rooms + sleeping room)

Technology/storage room/pantry
I would divide it into a maximum of 2 rooms.

I had the same idea in mind before, I think I will implement it as well.

The pantry is a matter of taste. Even if the room is unheated, it will no longer be properly cool.

Why do you think it won't stay properly cool?

What is missing is a coatroom.

I would imagine the small niche that is drawn in like this: as shown in the attached picture.
Otherwise, could something still be planned under the stairs? yes no??

Do you need the guest room? Or should it be the office? I can't tell from the questionnaire.

In my opinion unnecessary "laundry room" results in the bathroom having only a rather small north-facing window, which would be too little for me given the size of the bathroom. That then doesn't have much to do with a daylight bathroom.

The question would be where else to put the washing machine and dryer??? I personally find it nonsense to place this on the ground floor when all bedrooms and children's rooms are on the upper floor, where all the wardrobes with clothes are also located. Bringing the dirty clothes to the ground floor to wash them there and then bring them back upstairs is, for me as a man who also does laundry and has no problem with housework, unnecessary work.

I also fully agree with you about the daylight. How else could I do it?

Do you need the guest room? Or is it supposed to be the office? I can't tell from the questionnaire

Guest office room, you have to put your paperwork somewhere, and on the other hand for family & guests from Italy or Slovenia.

What did you have planned for the room?

Houses nowadays are really well insulated. There are no cold bridges, nothing. Your pantry is surrounded by the 2 warmest rooms and the hallway which also has its 20+ degrees. Unheated, you will always have your 20 degrees. With tilted windows, a bit less. Even my insulated, unheated attic was not colder than 15 degrees and the windows were tilted in winter.

Pretty cupboard

It is always a bit messy.