I wanted to create open space as much as I could and to make entire house look as much as luxurious as it can be, in terms of surface planing, so I have started with ground floor first.
Ground floor have open concept, it is increased for terrace that was in a project before. Now there are two sliding doors that opens to the outside, and with possible glass fence panels, you can get really good effect and feel that your are almost outside. *
( please check rendering image ).
Kitchen is the same as you added , except I have cut corner piece so you can have fireplace. I really liked that part as the nook where you can enjoy wine as the column in the center become multi functional unit for TV on one side and wine storage on the other. You have three fireplaces on the ground floor. One of them is new and is placed in formal living area while the two are in kitchen / dining / living room.
For the basement, I was really inspired with the house size and I wanted to give you something grandiose. That is why I made completely separate master suit. It has entree, master bedroom that opens to the outside, big walk in closet that has a make up table and central island, and master bathroom. I really imagine this can look amazing, with selection of materials and furniture pieces you can feel like you are in a resort. But you can be there everyday.
Other wing of the house is dedicated for kids bedrooms, and their bathroom. With big glass panel doors they can easily go outside and enjoy your yard. All the bathrooms are one beneath others so you can make pipe web easily. Next to the kids rooms is place dedicated for office. I wanted to use existing window as in 3d that you gave us. And as office doesn't require a lot of light this window will provide enough of it.
At least gym is in the corner of the house where I wanted to open windows on both corners so you can have a lot of the light. There is spa tub, and closed sauna.
With dedicated interior process, this project can make statement in terms of both design and living.