I have to confess - i buy this by the bolt when i have a 50% coupon at JoAnns - which is usually at least 12 yards....but i don't wash it til i am ready to use it. I cut the needed size...with about 6" extra for shrinkage - and wash and iron only what i need for the quilt.
Perhaps...if you really want to wash it now - You could smooth it well and fold and could save the ironing til you are ready to use it - then have to iron only the portion you have cut off for your project ?