I’m afraid that is not really a practical option. When I visit the US I do use my Japanese SIM card, because my carrier here, Softbank, also owns Sprint. So I get unlimited use of data and talk while in the United States.
But the reverse sounds complicated very expensive and I would probably need another device.
VoIP is really designed for people in my situation I feel.
I just need to find in app that fills in all the gaps.