sabbaticalhomes.come is a great place to advertise your house and find a new one
You can elect to pay for UBC's extended health care when gone, but Sun Life's Europ Assistance plan will only cover emergencies while you are away. Also, if you go on unpaid leave, Sun Life's Europ Assistance only lasts for 60 days.
There are various rules that the US government imposes on non-US citizens re health insurance if you want to hold a J1 or H1B visa. I was advised by Stanford that the Liaison® Majestic Program offered by Seven Corners is a good medical plan for people going to the USA with a family. http://www.sevencorners.com/forms/3LM09.pdf