I blocked Sarah's quilt once the quilting was finished (and also mine) and I can tell you that there isn't much bleed with these fabrics. I submerged the quilt in water, took it out of the tub, pinned it to the floor and let it air dry.
The way to get around bleeding (though that has really been something the fabric companies have pretty well taken care of) is to simply wash your quilt with a couple of Shout color catchers thrown in.
As far as there being enough yardage to pre-wash, I can't say. I just hope you remember to wash your backing as well!