So what's the dilemma?

Posted a rough floorplan of my historic cottage home m it's currently a one bathroom and I want to add a second bathroom as a master bath but I'm running into a bit of a dilemma.

Second image is the basic location for the addition, third is an idea I'm toying with to close off the master suite from the current "shotgun home" style connection to the living room where you can walk from the living room, through the master, and into the back bedrooms. Basically, I'm thinking of closing that wall off, and furthermore giving the master a his and hers closet.

Any thoughts or ideas from the crowd on this one? Am I missing some sort of appeal of the door at the front of the house? Or the historic consistency of the walkthrough floor plan?

I think I would want the master suite to be at the back of the house away from the street in a more private location. That last bedroom adjacent to the utility room seems to be a good location with plumbing already accessible.

Unfortunately there is a detached garage that crowds that space, and all the utility tie ins are back there as well which would require them to get moved. Also, I just roughed this floorplan so the scale is a bit off maybe, the back bedroom is definitely the smallest.

I've good over it with a few builders, and the spot I've highlighted really is the only place to do the addition. The question is really just whether I should close off that doorway and go to the added expense of reallocating closet space or if that's the kind of thing that may a) remove some of the historic charm of the house or b) be a bunch of additional expense that future buyers will not attach any value to?