It's a very good and interesting question I am sure it affects many women and women who have had to cancel plans too.
Personally, I would not want to keep it.
I think it would be great if you gave it to good-will/charity. Besides those very cheap imports that seem to be made from lining material. Lots of women could not hope to afford an average priced wedding dress. .
Sell it for money on ebay. Sell it for less money on local ad sites. Donate it to a good cause (would womans shelter accept it?). Pass it on to a distant friend. Create a new dress out of it. Make craft art out of it. Make curtains