Take a look at the thread from #66.
When skimming through your thread, the basic facts such as entrance east, (extreme) slope, garden in the north, basement due to the slope (living area there because of the slope), desired rooms, etc. are the same.
The other design had the problem that the plot was very narrow; additionally, grandpa should have several official living rooms in the basement, the children's rooms and a children's bathroom were to be on the upper floor, and the access to the house from the plot came from the south.
You don’t have these problems, so a feasible and nice design should be possible for you, right?!
If you could upload the building envelope, the plot dimensions and/or a few photos of the plot, I could adapt the previous design somewhat to your wishes.
The heights are clearly visible, but screenshots in relatively low resolution are not easy to read.