sorry i have some info mixed up, i think i purchased a temp sim card with T-Mobil before i leave the US, since i remember GV required a real # (not virtual phone #) for the confirmation code when porting. Thats what i remember since its quite sometime ago.
i completely cancelled my US T-mobil plan about 1 month in advance and port the # to Google voice, since i wanted to test it and make sure everything works before i actually leave. i was only using the home Wifi for 1 month (but since i work at home so its ok). i purchase a Thai physical sim card at the AIS store here the day i arrived - of course with help of a local Thai. you can also get a temp esim in advance and activate it the day of boarding plane and it will auto connect once you arrive. and my plan is to get a temp esim if i need to visit the US.
have been using Google voice for 1 yr since i moved.
If you still have bank account or other US base services, better to keep the US #, and add a local Thai # on the same phone.
If travel back to US just buy a temp sim card for US only say 2 weeks just for internet and as long as u have internet service ur google voice will work.
This is something that i really dont understand and annoy by it.
If a person is asking a question that has been answered 16 times or 1600 times. Those people that are so annoyed by it would not just skip it, but no they rather take the time to reply with some stupid and disrespectful answers. Whats up with that?
