I really really want [[https://www.asos.com/vero-moda/vero-moda-ruffle-one-shoulder-floral-maxi-dress/prd/9773804?clr=multi&colourWayId=15069039&SearchQuery=one%20shoulder%20dress this dress]], but it's only available from ASOS and only in a size L. I'd need a small, I'm around a size 8. Would a seamstress be able to alter it to fit? Or would it not work given the shape/fit of the dress?