I am not sure you can. We tried to add Canada to our Verizon plan for a trip a couple of years ago. When I had asked about it a month or so before we left, the staff at the Verizon store said no problem. When I tried to add it, just before we headed to Canada, they said no can do. So I don't know if I just got bad answers from the Verizon folks or if it is not available. We ended up buying a cheap prepaid phone so we could keep in contact with kids. And the per minute rate that the Canada plan charged was not cheap. Probably would have been just at cheap to use our Verizon phone and pay the roaming charges.
