I am traveling tomorrow (Mon) from BKK trying to get back to SJC/SFO on a OW150C OneWorld award on AA miles. I have a massive layover in NRT that I'd like to avoid since for various reasons I'd very much like to get home as soon as I can.

I am currently booked on the 11:30a CX flight BKK-HKG (50-min connection - yikes!) connecting to NRT on the 16:10p-21:25p flight. Then I have a whopping 20-hour layover before the NRT-SJC AA flight on the 29th (17:15p)

My question is, what are my options for avoiding the layover / getting home sooner:

-(1) I was thinking I'd try to show up at the airport in time for the 8:00a flight to HKG, and try to beg for a boarding pass for the direct flight on CX from HKG-SFO. I'd be happy to take a downgrade to coach to get home a day sooner ... but as my ticket is thru NRT connecting to AA, and the OneWorld award rules don't seem to permit a change of routing (or class of service, at least on a confirmed ticket), is there any chance of this working? ... A related strategy involves the HKG-LAX-SFO routing.

Any other ideas?

Also, any ideas for what to do with my 20 hours in NRT without breaking the bank?

Best regards, and thank you for your help!