Oops, yes, should've mentioned I am a UK citizen so can use the E-gates at the border. It's a PRG-LHR-JFK connection in F.

Thanks for the responses. Assuming I arrive at T3 on schedule, I think I'll try Option 2. I've done the "official" Option 1 route a few times, so I'll see how a different way works out.

I'll set my stopwatch and report back with CWS-style timings.