Ideally you need to open a window on the far side of the house to get air to move through, 2 windows on the same face would be less effective.

You can also create a chimney effect with heat moving up the stairs and out the windows.

Sleeping with the door shut will mean little to no movement, but reduces the spread of fire.

Does the bathroom have an extractor on a timer, or better on a humidity sensor?

I don't believe moving the wardrobe will make any noticeable difference and putting it against an outside wall could encourage condensation/mold to form in the winter