There's currently a massive unadvertised sale on flights from Vancouver to Hong Kong on Delta and Alaska Airlines, with prices well under $700 including tax round-trip for flights September to November.
Fall is a great time to visit Hong Kong, with warm temperatures, lots of sun, and lower humidity. The mid-autumn festival in September is a week-long celebration that hearkens back to ancient days, when farmers gave thanks to the moon for a bountiful harvest.
Hong Kong is also a great jumping-off point for travels anywhere in Asia.
The flights have one stop in Seattle, and total flight time ranges from 16 to more than 30 hours each way, so check your flight times carefully to ensure you get the flight that best fits your needs. Book your flight with Flight Network, and you are protected if the prices drop even lower (which seems unlikely, but you never know!). Look for flights any day of the week except Friday or Saturday.
If you prefer a direct flight to Asia, Cheapo Air has direct flights to Shanghai on China Eastern for $713 including tax starting in October, and you can save an extra $15 with promo code CHEAPOAIR15, bringing the cost under $700.