I had a flight to depart from Vancouver Canada to Paris (non-stop). That flight has been cancelled and rescheduled for the next day. No other non-stop flights that day from Vancouver. I live between Vancouver and Seattle and would like to switch the departure airport to Seattle which does offer a non-stop departure on the day I need. I plan to call but I wasn't sure if a change in departure airport was allowed. The distance is ~150 miles, so beyond the 100 miles that is normally listed as acceptable alternative airports. Any advice on being able to get this change in place without paying extra for an airport change?