Impossible to change region width/height?

i’d like to change width of T,N or other type of panel in blender with python, but it seems that it is impossible ?

for ar in bpy.context.window.screen.areas:
    if ar.type == 'PREFERENCES':
        for reg in ar.regions:
            if reg.type == 'NAVIGATION_BAR':
                reg.width = 1 #nope -> read only

is it really impossible ? all i want is to close this panel.
(by the way there’s also no operator to toggle the navigation bar. it’s kind of annoying as i use my addon pref as a little asset management system.