Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Hong Kong to Portland, Maine as you normally would.
Hong Kong Intl
Portland
2 stops
34h 57mPortland
Hong Kong Intl
2 stops
34h 45mUnited Airlines
Hong Kong Intl
Portland
2 stops
24h 18mPortland
Hong Kong Intl
2 stops
24h 45mUnited Airlines
Hong Kong Intl
Portland
2 stops
22h 14mPortland
Hong Kong Intl
2 stops
35h 00mUnited Airlines
Hong Kong Intl
Portland
2 stops
34h 57mPortland
Hong Kong Intl
2 stops
34h 45mUnited Airlines
Hong Kong Intl
Portland
2 stops
24h 18mPortland
Hong Kong Intl
2 stops
24h 45mUnited Airlines
Hong Kong Intl
Portland
2 stops
22h 14mPortland
Hong Kong Intl
2 stops
35h 00mUnited Airlines
Hong Kong Intl
Portland
2 stops
34h 51mPortland
Hong Kong Intl
2 stops
31h 00mDelta
Hong Kong Intl
Portland
2 stops
45h 54mPortland
Hong Kong Intl
2 stops
55h 00mDelta
Hong Kong Intl
Portland
2 stops
45h 54mPortland
Hong Kong Intl
2 stops
53h 00mDelta
Yes, there are multiple flights from Hong Kong to Portland, Maine for under HK$11,300. The cheapest flight booked recently is on United Airlines for just HK$11,220, but on average you can expect to pay HK$12,389.