We just moved our wedding date up due to military stuff and only have about 1.5-2 months to plan EVERYTHING. Bought my dress off the rack this morning!

My question is, is it possible to find dresses for my 4 bridesmaids this quickly? Two live near me and two are out of state... Has anyone done this before, or seen it done?
Obviously we don't have time to order dresses for everyone. Since our guest list has shrunk by 70% and coordinating the girls could be difficult, I'm considering having only my MOH and fiancee's BM stand up for the ceremony. Then it would be only one dress and much easier to find. I talked to one BM (My SIL) about it and she seemed understanding of the situation. What do you think? Rude to "unask" my BMs for this, to save us all some stressful shopping? If so, any suggestions for coordinating?