Here's one suggestion: Depending on your layout, one vanity, one medicine cabinet, plus one floor-to-ceiling "built in" (like 18-24" wide, 12"-16" or so deep) in the corner (provided you have some floor clearance in front of it). If you keep things tidy and organized, leave it with an open front (no door) and shelves relatively far apart. Very useful and retains an open look.

Consider framing it to accommodate a pair of doors or curtain in the future, just in case.

Go to the bath forum and post your floor plan. We can bat around some options for you there. IMO, you can never have too much storage, but obviously your room needs to be able to accommodate it.

Thanks to both of you hb and wa. I should have mentioned that we don't want a vanity either, especially as we installed a new pedestal sink a year or so ago. Btw, I did just post this same question at Bathrooms before posting this answer. Also, it does look as if I am going to have to include photo(s).