Keeping US Number -

Hey folks, coming over for good in October - I need a US number for ONE reason only - 2 factor authorization!! Literally every day, for banking, Paypal, government, practically anything I log onto here, they send a text to my US number so I can log in. Of course I will have a VPN when I arrive, but how do I keep a US number [JUST to receive texts, won't be making or receiving calls with it!!]. I will keep my phone from here, and buy one there with a Thai number - how can I go about making/keeping this one as my "US phone''? Thank you

Have any other UK citizens successfully dealt with two-factor authentication with their UK numbers in Thailand? I've racked up heavy fees previously by having to turn on my UK sim to authenticate and wondering if there are methods to get around it.