Hello,
As you mentioned, there is only one window in the room, the window is big but maybe not enough for the room and the room don't receive enough light. So I started to the project with considering the lack of 'natural light' element.
I thought on this topic and decided to cover almost all of the opposite wall of the window with mirrors to reflect the light coming from window. To achieve that effect, i chose to use the wardrobe space for the wardrobe again, but the new wardrobe has sliding mirror doors. And to complete the wall, i put full-length mirrors (different widhts each) on the wall part next to the door and part of the wall on the vanity - wardrobe axis. I moved the radiator on the same wall.
Because of there is not enough natural light, i decided to use lights but you can change the density of the light with special switches. Also I put adjustable lamps on night tables so you can make the lamp higher or lower just how you want. And the almost diffused led lights next to the panels on night tables and on top of the bed (surrounding the world map) creates a beautiful effect.
There is a map on the wall (top of the bed) for you to remember all of the beautiful places you have visited and memories you have collected. (Also with lights)
The bed is queen-sized and has 2 drawers under it. Or if you prefer you can use a bed frame with thin legs and put storage boxes under it.
Added a small vanity area, in case you ever need it.
And used a warm yellow color in some parts to bring the design together and to add some interest.
Hope you like it, have a beautiful day.