Making a day plaid (aka laird's plaid)

[Tobus]

When I ordered my Reproduction Colquhoun tank from Barb T. a while back, I went ahead and got extra yardage for future projects to ensure that the tartan matches exactly. This is double-width cloth, and I have 5 yards of it (plus the scraps left over from the kilt-making process). One of the projects I wanted to do was to make a day plaid or laird's plaid.

Since I know there's a lot of confusion on terminology, what I'm planning to make is shown below:

The fellow at front center:


Several examples worn by MacDonald chiefs:


On the left:


I've done several searches on this forum and found discussions about how to wear them, etc., but what I can't seem to find a decent answer on is whether there's a correct size to make them. Does it really matter? I've seen references to them being 60" long or 72" long, which seems to be a pretty significant difference. Or should I just tailor it to my height so that when folded length-wise over my shoulder and draped evenly, it falls to a specific point on my body?

As for construction, since I have double-width cloth, it should be fairly simple. Just cut it to length, fringe the ends (I will purl the fringe to about 4" lengths), and that's it. My only real dilemma is on the length to cut. Got any pointers?