i was going to suggest rolling it on a tube and storing it in a dark closet covered w/ just a sheet. Rolling it will prevent the fabric from creasing and breaking.
My mom stored her wedding dress on a hanger covered to protect it from the dust and it hung in the closet for many years - when i looked at it, the only thing that happened was some tears at the shoulders.
My ex-husbands mother had hers stored in a box - wrapped in tissue & treated, etc (this was 50 yrs ago/25 yr at the time) and when we looked at it - the dress had holes in it from being folded up in the box.. It also hadn't yellowed evenly because it was folded up. My mom's dressed aged more evenly because it hung on a hanger & only holes at the shoulders