redbowls,there are not many people from Oakville here,only 2 I think.
However,since Jack is an indoor cat,he probably is not far away.
It's been suggested to put things outside familiar to him,his litter-box,some really smelly food,like Tuna,maybe a blanket with his scent.
Also,grab a flash-light and look for him after dark,the flash-light will makes his eyes shine,knock on doors and ask to look in backyards.
Hope you find him
,I just noticed he ran off August 6th,that's quiet a while ago,maybe someone in your area is feeding him and caring for him.