A real floor plan with ALL dimensions, reference pictures and some idea of what can and cannot be moved would help you get advice. That and your budget.

You could probably tuck a bath in another spot if you have the budget for new plumbing including septic), new fixtures etc (that would be a $50+ thousand project where I live) - new bath would likely impact bedroom sizing in some manner so think whether that is doable -

then you’d likely combine both current baths into one larger primary/master bath -

an architect could help the best with practical ideas

This would give you an extra 18” or so in each bath. Not sure if the bathroom layouts could benefit from that.

What about something like above comment but use the new space entirely in the master BR and put a sink/vanity out in bedroom and have the current bathroom be just the toilet and shower with maybe a small sink for washing hands.

The closet takes up precious floor space. What if it were gone? Bed and closets could be designed on the far wall.

When closet is gone, think about moving master bedroom to the left.

When people renovate to make a luxury master bath, it often comes at the expense of a bedroom (giving a large closet + large bath). I don't think you want to do that here, so make the finishes in your master as beautiful as possible, and pack it full of storage -- medicine cabinets behind mirrors, extra cabinetry, etc. If you really want a little more, like for a larger vanity, you could give up a foot or two of closet in exchange for a couple extra feet of bathroom length.

It's nice that you have linen closet in the hall and smaller bath, so you don't need that to fit into your own bathroom. Anyway, my imaginary 9-foot length allows for shower at the far end, toilet, and a 48-inch vanity. That allows a lot of selection, for your desired balance of style and function.

Oakville Bath Vanity, Ceramic Sink, Walnut Ebony, 48 Inch, Satin Brass Hardware · More Info

48 Inch Single Bathroom Vanity, White, No Top, No Sink, Transitional, Outlets · More Info

48 Inch Dark Gray Bathroom Vanity, No Countertop, No Sink, Transitional · More Info

California 48" Bathroom Vanity, Sage Green, Carrara Marble · More Info

Deluxe Series Medicine Cabinet, 24"x30", Stainless Steel Frame, Recessed · More Info

Anyway, moving walls and starting all over with finishes will be pricey, but you should be able to make something worth living with!

West Palm Beach Meadow Residence · More Info

Courtyard || Remodel || Austin, Texas || Bathroom · More Info

Bluffview · More Info

1423 Alexander The Marvelous · More Info

Williamstown - Project 1 · More Info

Good luck!

Here is another one. Be sure you go for a vanity that's less than 2 feet deep, so that you don't feel crowded walking around. Four feet is tight but workable. A wall-mounted toilet is pricier than standard, but also helps a room feel bigger.

Turnkey Garden Flat · More Info

Toilet Room with magazine rack · More Info

You don't mention what amenities are there currently, and what you want to add or change. If money is no object, then get an architect to work on a new layout/plan (cha-ching). Have you considered converting the space to a full on wet room that incorporates tub, shower, vanity and toilet, all in luxury of course :)