The blades stayed on, but were supported by two poles that were placed at either end of the trailer bed. We also would put wooden chocks between the mast and the head to prevent any teetering. We also removed the horizontal stabilizer. As far as distances go - when I was there the furthest we went was from San Diego, California to Phoenix, Arizona. A good 8 hour drive. The trailer was custom built. I'll see if I have any more photos at home.
I have also seen people use a similar arrangement for R22's. As long as the blades are supported there doesn't seem to be any problems. I'm not sure what people did to support the blades because of the coning hinges, but like I say I've seen it done.