Thank you for your fun project. I created 2 alternatives for the plan of basement and ground floor. The first one is based on extending 1.5 meter to the north in the sleeping area to allow you to have 3 bedrooms with all the facilities you need. Second on is based on the current situation of the in order to lower down the costs. In first alternative you have 6 bedrooms 1 in the basement 3 on the ground floor and 2 on the top floor. However in alternative 2 it is 5 bedroom in total.
The living room and dining room are close to the screened porch to allow you to go out at any time and have the view of the lake. The outdoor kitchen is close to both dining areas inside and outside in case you have guests. The kitchen has a storage area for pantry and a small sink and may be used for appliances on the counter. The door to the storage room can be designed in a way to look like a cabinet door in order to make the whole kitchen harmonious.
In The outdoor you have all the spaces that you might need for relaxing or hosting guests. You also have a fire pit and seating area around it. And also sun beds for relaxation after using the bath tub this area can be without roof. But the other part of the porch can have a roof for more protection from the sun.
Hope you enjoy.