More thoughts on this 2-factor problem. If you have a trusted friend in USA, use their phone number for the first number (and have them whatsapp you the codes when they come). Once that is working add a second number using your google voice as a work number. You can say that it is mobile and get it verified. Once that is done, just make it your primary number and delete your friends number. I'm pretty sure this will work. I definitely checked my account and I have my USA Verizon cell phone as my mobile number and as primary and my google voice as my work number (with a notation that it can accept text messages). When I log in and it wants to send me a text, it gives me a choice of either phone number. When outside the USA, I always choose the "work number" which is google voice and it always works.