[Bibio]

make a velcro extender.

its very very easy and no sewing required. but 1/2mtr (of hook and loop parts) of the same size or slightly larger adhesive velcro as on your jacket collar. cut the velcro parts to the required length. stick the two velcro parts together to form a hook side and a loop side so its one piece of fabric. attach extender to velcro on collar between the original velcro on your collar...