Most confusing. At the beginning the OP says they were flying from YOW to YSJ but later after many convoluted sentences it appears they were stranded in YSJ trying to get to YOW. Was the fog in Saint John or Ottawa? Airlines no longer offer compensation for weather caused delays unless you are in mid-journey and it is hard to protect people on future flights if it appears the weather issues will cascade into multiple flights involving hundreds or passengers. That's one of the reasons trip delay insurance is sold either as an option or as a feature of most premium credit cards.

So suggest OP checks to see if the cc used to purchase these flights offers this coverage and if so, initiate a claim with the insurance company.

That's the reality of modern air travel.