[Nate tha' Great]

This is a Button versus blinds confrontation so I think it's probably wrong to assume that he needs exactly AA or KK order to 5-bet; that said I think he's going to have one of those two hands a pretty good percentage of the time.

Meanwhile, the 5-bet has made the pot so large that I can't imagine folding before showdown unless the board gets really scary.

That leads me to believe that calling down is the best play, starting with the flop. Don't fold.