It is universally accepted that length and width are not of primary importance, as the videos demonstrate these areas can be easily adapted to the shape of an individual's foot. As a general rule ski boots can be made bigger but they can't be made smaller.
This video illustrates the modifications that can be made and the equipment you would expect a good boot fitter to have.
Its highly unlikely that you will find a ski boot that fits perfectly out of the box. The design work is done in one size, usually Mondo 26.5, from that size the boots are simply scaled up or down. The human foot doesn't scale in that way, large and small feet have different proportions.
