I recently moved to Denmark. One of the worries I had was to keep my phone number to allow two factor authentication. Of course I updated my contact information on all important pages, but I was worried I would forget some. Some pages just straight out would not allow a Danish phone number to begin with.
Google Voice comes to the rescue. When I cancelled my Google Fi service, I just choose to migrate my number to Google Voice and it was as easy as that. Can receive SMS and voice messages to keep the two factor auth going.
Of course there are some pages that filter based on IP address. One easy solution was to use the built in VPN that comes with Opera browser. It won’t break any speed records, but it allows you to log into most American web sites that filter based on location.