I had the exact same issue coming out of Halifax a couple of months ago. Weather in the Toronto/Montreal area disrupted my trip home - no flights could leave Halifax to those cities meaning I couldn’t meet my connection, which ran to time.

I managed to persuade WS to put me on the direct service to LGW instead, which was a painful flight but at least I got somewhere close to where I had intended to be. Successfully claimed ORC too which was nice. (BA flight was in J).

rereading this, it doesn’t appear to help the OP at all. Oops.