I’d do the Ripple-fold drapery wall-to-wall, floor to ceiling, on a ceiling mounted track. No cornice. You’ll probably need almost all of the wall space for the drapery stackback. If the room is not large, a gray similar in value to the wall color will blend with the wall and make room look larger, though a slightly darker gray that provides some contrast could be more interesting.

I don't think it's necessary to do a ceiling track since you have plenty of wall space above. I wouldn't put a cornice since it's a door. They sell decorative traverse rods, so you don't need to hide it.

Also look at white fabrics that match your trim if gray is trending out in your area.

no cornice

I am not fun of cornices. They look dated for me.