Run away gun said:
Not when you factor in the costs of construction and maintenance of runway, taxiways, passenger terminal, and other facilities mentioned, and all for very limited use.
The grass strip on the Mattawa exists as an "austere" landing strip for training Herc crews. It can stand one, or perhaps two, touch-and-goes by aircraft with no loads and then needs a rest for a few weeks as the surface will break up. It is only useable when dry. I had to investigate an incident somewhere in 1990 or 1991 when I was G3 Aviation/Base Flight Safety Officer after six Hercs in a row did touch-and-goes one night. One or two of them were rather significantly loaded and caused sizeable ruts. The final one caught the ruts and almost went sideways off of the runway but managed to stagger back into the air and return to Trenton with some minor damage. Note that this was at night, and there is no fancy lighting on the Mattawa; I can only imagine how long it took for heartrates to return to normal.
The grass strips in Petawawa and Gagetown were built for L19s used for Air OP in the pre-Kiowa days.
Should it ever be decided that traffic would warrant a full-blown facility capable of handling C17s and/or Airbi, then enlarging Pembroke would be the more sensible option - except to the landowners on either end of the current runway - and "more sensible option" is only marginally so. Neither would be worth the cost.
