Bespoke waistcoats

[AKScott]

How much adjustment could reasonably be built into one of these?

This is the sort of thing that ought to last me 20 years or so; but dash it all the muscle in my chest and shoulders keeps taking extended vacations around my belly button, so what my waist measurement might be 20 years from now is, ummm, a mystery.

Could something like the first pic in bias cut tartan be made to fit the same waste measurement range as the kilt it would match? I could probably settle for that, something like 36-40" waist?

EDIT: would one meter of double wide be more than adequate for one vest probably?