I assume the double doors are the entrance from the bedroom? In general, I would want to add the space to the closet, as it is relatively smaller than the bathroom, but i don't care too much for a configuration that you walk through the closet to get to the bathroom. Can you add the current bathroom layout to your sketch? That will give us an idea of what could be rearranged to accommodate a potential vanity inside the space. What else do you want to change about your current layout? What are your goals?

I just finished an addition to my twenties home. I tried everything to get a bath and closet with in a 13 x8 ft space but everything felt cramped and instead of having a tight closet and a tight bath with small shower and vanity we decided to add wardrobes to or large bath. I wanted custom but due to an unexpected health issue we scaled back budget and went with IKEA pax wardrobes they hold all of my most worn seasonal clothes and all of my husbands work clothes plus most worn casual wear. I like the reach in better for organization too. We still have the orginal reach in closet and a pine older armoire for extra items in the bedroom but never open it. Could you add wardrobes in the bedroom and have a nice sized bath with additional storage? I really love my large bath after years in this old house with tiny baths and closets. I was unconventional and like keeping my clothes in the bath which has two venting fans. it is my most private from the street area in my room so it is where I change anyway but the wardrobes take up so little space I could have placed them in the bedroom without losing much floor space too. in your second plan you can turn the vanity and make it longer and have the edge abut the shower with a half glass panel and than the door....

Sorry I'm so late getting back to you. I think that oddly sized fixtures can be off-putting. Many home buyers are looking for an "ideal" and they can't see past that. If the tub is well made and the bath is located where it's most needed a shorter size tub might not be a problem. If the bath will be used by children then its size is less important, but children grow into teenagers. acm voiced a concern I had about the location of this bath to nearby bedrooms. My mistake in calling it water-resistant drywall. It looks like drywall but it's better referred to as tile backer board. It's most often 1/2 inch thick but I have seen a Hardie brand backer that was only 1/4" thick and came in 3 x 5 ft. sections. HERE is a link to more info on these. There are several types with differing properties. On toilet location, I don't think "obstruction refers to the nearest wall or fixture. I think it refers to something directly in front of the toilet. Looking at your floor plan an angled toilet would not have anything in front of it. There might be room between the toilet and the vanity for a waste basket.

Changing the toilet location is complicated and costly so I would keep it where it is. I would however swing your double vanity around so that’s the first thing you see when entering the room. I would convert your tub into a shower and get rid of the dividing wall. The added wall make the room look small and cramped. Below is a photo giving you an idea of what it could look like. The tiles you chose are fine, but keep the walls and cabinets light. Good lighting is essential, especially since you don’t have a window in there. Add a ceiling light in the shower, lights by the sinks and a strong combination exhaust fan & light.