Always worth a share! Salespeople do not always know, or remember to tell you, but you can get a lot of dresses in shorter AND longer lengths! If you don't get a confidant answer, ask to speak to a manager (or even better: an alterations manager!) long sleeve dress for wedding
ALWAYS speak to someone from alterations if you plan to have your gown adjusted in any way! The salespeople are not trained to tell you about what is possible/not possible to alter!