Since you asked, I'll tell you what happens. If the sponsor defaults, the government will definitely give social assistance to the person who is sponsored, the parent or grandparent, and immediately the next month the Canadian sponsor is billed, so the child who sponsored his parents will be invoiced the exact amount of dollars that the parent is given. That will be invoiced with interest and they are obliged to pay that within 30 days. If not, interest at 5% comes on, so there is virtually zero default in this country in terms of parental or grandparent sponsorship in that program.
On October 25th, 2016. See this statement in context.