. . . governed the other rings, but also allowed a skilled user to dominate the wills of all other beings in Middle-earth.  If Galadriel could defeat Sauron and wield the Ring (a big if, and as we know from Tolkien's letters not really possible at all), she could not only preserve Lothlorien, but extend the borders of Lothlorien until her realm covered all of Middle-earth. 

Saruman provides an example of how that realm would evolve.  At first the beauty of Lothlorien would remain.  But soon a corrupted Galadriel would begin to make "improvements," as Saruman "improved" Isengard.  And as her servants became slaves, they would begin to resemble orcs, and her realm would begin to resemble an orc kingdom.  Eventually all Dark Realms aim toward the fate the Barrow-wight describes -- a withered land, and a dead sea.

________________________________________

"‘I think he was a silly little man,' said Councillor Tompkins.  ‘Worthless, in fact; no use to Society at all.'

"‘Oh, I don't know,' said Atkins, who was nobody of importance, just a schoolmaster.  ‘I am not so sure: it depends on what you mean by use .'

"‘No practical or economic use,' said Tompkins.  . . .

. . .

"‘It is proving very useful indeed,' said the Second Voice.  ‘As a holiday, and a refreshment.  It is splendid for convalescence; and not only for that, for many it is the best introduction to the Mountains.  It works wonders in some cases.  I am sending more and more there.  They seldom have to come back.'"