contemporary floor plan by Steven Corley Randel, Architect - general sizing/space requirements for new master bath use as reference. i would switch the tub for a shower and use the old shower space for a bigger linen closet/ bath product storage
Bathroom in 'Carriage House' by Hare + Klein Design: originally built in 1850 as a carriage house, it was converted into a metal castings factory in the early before more recently being transformed into a home.
this towel storage tower is what I would like to the right of the shower (when you are facing it). On the back side I would like drawer cabinets, toilet side. We would take the space from the too wide shower to add this new wall of storage