Looks like I have to do a quick trip to PEK weekend after next. I can connect through either EWR or IAD. I would like some opinions on which looks the most likely to clear as a 1k. EWR-PEK is served by a 777-200 with 48J seats, IAD-PEK by a 787-8 with 36J seats.

Outbound 12/13 (Friday) (E fare)
EWR-PEK
J9, JN9, C9, D8, Z0, ZN0, P0, PN0, PZ0

IAD-PEK
J8, JN8, C8, D7, Z5, ZN5, P4, PN1, PZ0

Return 12/15 (Sunday) (W fare)

PEK-IAD
J9, JN9, C9, D8, Z7, ZN7, P0, PN0

PEK-EWR
J9, JN9, C9, D9, Z7, ZN7, P4, PN0, PZ0