In Alberta, the tenancy is broken when the tenant has abandoned the premises or when the tenant does something that makes the landlord reasonably believe that the tenant has ended the tenancy agreement. This is called "repudiation" of the tenancy agreement. Repudiation happens when the tenant does something that shows that he or she no longer wants to be bound by the terms of the tenancy agreement.
In your case, conclude the exit inspection (you have correctly given him/her two opps to be there), mail a copy to the last know address (which may be the property in question, but that's okay). Assuming you have a security (vs damage) deposit, include a statement showing total rents owed to October less SD, which hopefully your lease agreement says you can use against unpaid rent. This is your initial claim plus un-recovered utilities. State in your letter that you both have an obligation to mitigate damages (re-rent the suite) and that a final accounting reconciliation will occur once the suite is re-rented.
Re-key and re-tenant the suite. Conclude your reconciliation and mail a statement and any refund within 10 days. I include $25 per showing as my incremental cost, plus any shortfall in rent recovery to the end of the broken term. You are entitled to sue to tenant in Provincial Court for amounts less than $25,000.
Meanwhile, use the opportunity to give a lightening fast turnaround to your suite with new paint, etc.!
Cheers
Chris the Mortgage Broker