Normally the landing interview takes a couple of months to be scheduled. I base this statement on others' experiences within this thread. The Calgary office may send you a letter, an email, or call you. I don't know. There doesn't seem to be a set procedure.
If they have approved everything and stated you will have a landing interview, then you should be just fine with your expired medical. If it wasn't okay, they would have sent you instructions to do another one.
Your spouse won't be away for months, will she? She should be able to attend. Some people have rescheduled their landing interviews in order for their spouse to attend (work commitments, etc.). I had to be there for my husband's landing. If the letter says your spouse has to be there, then your spouse has to be there.
Maybe someone else can help you with a contact number for the Calgary office, but for now, it looks like you will have to wait for them to contact you for the landing date, and then you will know if you will need to reschedule for your spouse to attend.
Edit: It wouldn't hurt to call the Call Centre once or twice to find out the average wait time for landing interviews for the Calgary office. While the answers are not consistent, at least they can give you a general idea of how long others are waiting.