Are the interior blinds in the door venetian blinds, accordian blinds or cellular blinds? You could do the same thing in a cordless option in an inset mount for the privacy, filtering, (and if cellular, insulation). I think a roman shade would be best for the over treatment since you want to furnish underneath. I might go up the the ceiling or crown moulding with a roman shade so it wasn't a sliver when it was fully opened.

Thanks for addressing the problem, P. I agree that any roman shade should stack entirely off the window area. The stack of pleats would be about half or less of what a standard window would need, so I don't think I'd go to ceiling--this is 8 foot tall room with a lot of oak frames at same top height--door to front step (behind the people in this photo), double sliding doors at closet (on right in photo), door to garage (at photographer's left), door to dining room and rest of house (behind photographer), door to basement (right of photographer). We're into doors.

The embedded blinds in the door glass are extremely thin venetian blinds. White. Jeld-Wen steel exterior door. In photo they are stacked at top--the mode for most daytime activity unless sun is very strong in summer. Faces west.

Here is a link that might be useful: The awning window under consideration

bumping this with the hope someone has an idea.

The room is definitely an accommodation to the oddities of the house design--writing it out in words makes it clear how hard it was to come up with a workable design. We're trying to make lobby seem to feel welcoming but also to lead people out to the back of house or over to the adjacent kitchen peninsula. Window is part of the welcome.

I ordered roman shades for our 5 foot awning window in our dining room. I don't mind the width, so did an outside mount. I chose the European fold option to make it a little dressy. Ours will be closed most of the time because it faces the side of our neighbor's house. I would have skipped it entirely, but the town did not count our back wall of windows and a french door as giving natural light or ventilation since they open into the screened in porch. The town considers those be on an interior wall.
Anyhow... it was the only way to get a window that did not interfere with furniture placement. Since it faces south, I wanted light filtering/blocking for sure. The Roman shade should give it a clean look and will allow ventilation if needed.

dianalo would love to see photos when installation is done. Thanks for posting

If you put a piece of furniture under it, I think you could put full length panels on each side, because they would be anchored by the piece underneath.

Palimpsest, thanks for the response. I did a lot of incubating about your suggestion.

I decided that I would indeed put full-length panels each side of the window. I had a piece of fabric that was paid for--had been purchased for the adjacent kitchen but rejected (too much rectangular stuff going on to compete with "shaker" cabs). There is barely enough fabric so don't look too closely on the back side at the false hem, etc. Local store had clearance sale on mahogany red curtain rod so I figured God was sending me in this direction. Rings were a lucky find at Tuesday Morning--they dropped the curtain so it just grazes the floor.

Not sure if we're going to keep this 1830s furniture piece or sell it, but for now, it's going to stay right here, my "plunk spot" for stuff entering or leaving the room. Front door will be painted to match the woodwork, once the weather warms up.

I still want to put a lacy or filmy or handkerchief lineny inner curtain over the window. Readers may have seen the Kitchens forum posting about decorating with old tablecloths on Take a Risk Day, but if you haven't, here's the link, much of it very silly stuff. Imagine that pointy white lace curtain here. (references to arrows and points in the postings deal with feng shui thread going on at that same time)

Here is a link that might be useful: taking a risk in decor--cut up a tablecloth?