Our interview took no more than 20 minutes.
As sponsor they asked me a few questions related to understanding the undertaking and what that means in relation to financial responsibility for my husband (i.e. welfare, etc) and as well explained the 2 year conditional piece. And then asked if I still wanted to sponsor.
Asked my husband what he has been doing in Canada, if he likes it, why we had two wedding ceremonies and a few other small questions. Then asked the few questions about criminal record, divorced, etc. They explained PR and the requirements to maintain status, as well PR card and when to expect it.
We were both anxious, but really nothing to worry about! I think a lot of people have even shorter interviews than we did.