I am a Canadian citizen and US green card holder. After receiving my green card I have been almost constantly away, studying in Europe for the last five years, and coming back to the US to visit my parents every 6 months to a year. I never applied for a travel document before leaving the US, so every time I come back, I have to wait for several hours at the airport before they threaten to invalidate my green card status and I try to convince them that I intend to return to the US after my studies. I have apparently been successful so far, but now that I'm actually finished with my studies and don't have any plan to move back to the US, I'm worried about what will happen on my next trip (which is very soon, and it's been more than a year since my last one).
Technically speaking I believe I have the right to enter the US just as a Canadian citizen, but as soon as they find out I have a US green card, they mark me for further questioning. My question is, what is the best approach to take next time:
Should I attempt to hide the fact that I have a green card (and only show my Canadian passport)?
Or should I show both documents and just accept that I will have to spend several hours waiting to be questioned as usual, and end up losing my green card (which to be honest, I don't mind losing too much)?
With the first option, I believe that technically my green card is not even a valid document for entry to the US at this point, so I don't think it would be unethical to not even mention it at all (or maybe not even have it on hand?).
With the second option, can I be sure that, even if they invalidate my green card, that I will still be allowed to enter the US on the basis of my Canadian passport?
Related question: Will a green card holder have problems returning to the USA after more than six months away? I believe the answers there make it clear that my green card is not a valid basis for re-entry to the US after more than a year.