NYC-FRA-SIN for sure. NYC-FRA you can slum in J then use a GPU to UG FRA-SIN. FRA-SIN is a tough upgrade though, only 8F seats on the 388. Just flew this 3 days ago and my UG cleared after some asking around manually in the Z-gate SEN lounge ... The FCT is fabulous :) But there is a risk that FRA-SIN will not clear.
Next best I'd say is ANA with IMO a greater chance of clearing.

in the FCT ... a 16 hr layover is a very acceptable situation ;)

I just booked this route a few days ago, leave Sunday. Ended up doing EWR - SFO - SIN on the way out. No F but I seem to prefer that route for a DreamLiner on the 15 hours UA1 leg.. On the way home I booked SIN - HKG - EWR and used a GPU on the first leg to get out of 2-4-2. Primarily booked the route to get home mid day, but got to burn a GPU.

I was considering ANA through Norita just for that little sushi bar where they overflow your saki into the wooden box! Alas I'm hooked on dollars on UA metal to secure GS.



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And you can spend 3 hours and €99 for a Porsche joyride on the Autobahn :D

Doing that coming off a red-eye just adds an extra little rush to the experience.

I'm with everyone else. go through FRA. very good chance of your GPU clearing. On your layover, rent the porsche. Return it, then take a train to Mainz or Wiesbaden and hang out for a while. Then relax in the FCT. Or just spend the whole time in the FCT :)

Opted for NH for JFK-HND-SIN. D class so I had hope for the GPU to first since plenty of unsold seats...but to no avail with under two weeks to go...