Is this a long narrow bathroom? If so, how wide is it? Can you share a picture of the opposite view?

A curtain - If you do go that route, a rod would be better. What's the height of the ceiling, standard?
But it leaves the place messier, doesn't seal water out half as much as an actual door. It's pretty inconvenient, particularly in a small space.
Why don't you think there's room for a door? An inwards-swing door may well work, or even a 3-panel sliding door.

Are you sure you cannot get a glass door only to work? Did you talk to a glass shower door company?

There is no room for glass nor do I want it in that bathroom. The entire bathroom is 2’3” wide by 7” long (as a *full* bath). It’s in the office (old “maids room” in our prewar apt) and won’t be used often for showering. So I’m not worried about constant use, I just want it to be functional when necessary as a shower, and pretty otherwise when used as a powder room. That is also why I’m not as interested in spending on custom glass panels. Furthermore it drives me nuts that there are not enough options for brass hardware for glass panels, i have ordered all the samples and none match my finish (see photo).

Anyway, I digress...anyway, definitely a shower curtain for this bathroom. :)

I like your hanging idea. If you can find a curtain that will go to the ceiling, that’s what I’d do. Standard shower curtains are only 72 inches.

why is there no room for a glass door? if it opened inward, would that work?

I saw this link to extra long curtains and liners in another post:

http://ceilingshowerrod.com/new/curtains.php#liners

I have a rain shower head and there is no splash until the water hits your body. So if you want to position the shower curtain lower than the head, so that you can still see the pretty brass shower head, I think that will be okay.

In the far upper right corner, you can see that my shower head is well above the curtain. We get no splashing outside. Just make sure the curtain is as tall as the people who are showering. A standard 72" curtain should work.

I have to ask....how do you shut the inward closing door? Wouldn't your body be in the way? I would get a tension rod with a curtain.

^^^very pretty solution

FWIW, inward only glass shower doors are against code here. In an emergency, (eg occupant fell), rescue must be able to access the shower area unimpeded.