It’s dirt cheap to get an unlimited data sim card in Thailand. I pay 15$ month for dtac. And I have a second usa phone I only pay 15$ month for just so I don’t run into issues while in Thailand. My suggestion is wait year before you decide to ditch your usa phones. I bought a used iPhone 12 because it was the last phone that uses SIM cards. You don’t want to be stuck in Thailand and not be able to contact your banks in the states.