Well as the guys at Boeing Tech are fond of saying, "ETOPS is ETOPS is ETOPS".
I should have known the NAT thing would have confused you
Regardless of what ocean or remote part of the world your operating over, ETOPS is basically the same be it 120, 180, or beyond. Freight operators have some leeway.
Like RVSM there is no one set of regs that covers all operations and thus a lot of it is left to the individual FAA POI's oversight. There is an Opspec for the NAT, CEP, NoPac, SoPac, Polar, AMU, along with an ETOPS OpSpec. The CEP is rather benign so maybe you're operation is slightly different, but I doubt it. Care to tell us what kind of operation that is, PAX, FRT?