If you have a contact in Whistler talk to them about how cold it will get there. An Airstream is not designed for cold weather no matter what the ads say. Consider the fuel cost and the safety factor of the heater on Full Time.
My sister in law spent a winter in Texas in here Airstream and had ice on the inside of the trailer more than once.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles