The last picture leads to the kitchen pantry, which is BIGGER than my bathroom. Go figure.

What about making the whole room a "wet room"?

Where is the door(s) located in this 4x11?

And could you (they) make a small addition to this bathroom by adding a stud framed wall, as if it were a hallway, so the vanity for example can be outside this 4x11?

Can they create a seat for you in your shower area? Under the window?

I like Carolins idea!

I think Lyn's photo is the best you can do with the space. Tile it all in a show stopping way..

Or make it a wet room - which you still have time to do...

See if they can install a pocket door instead of a standard door.. we just did that in our bathroom remodel. Love it it! It will save space!

The sketch showing positioning of items by lilion is the way to go.
If the door can be a pocket or barn style, all the better. If positioned in the centre line of room, then switch the toilet and sink, so the sink/vanity becomes 'the sight line' at the opening into the room.
('The first thing you see' rule)

One trick we use in narrow, old Toronto houses is to custom build the vanity at 18" deep (you can find a sink and faucet that fits) and also banjo the counter top over the toilet - to make it look 'longer and leaner'!