All they require to access your wallet, is your seed phrase they actually don't need your device or have to change your password. Once they are done withdrawing your funds there's actually no use of the wallet anymore.
. Will the person be able to withdraw your money or change password and block you from having access to your wallet?
Changing password actually depends on the type of wallet you are using, some wallet require some verification via sms or Gmail before you are being able to change your password any no one will be interested in wasting time doing all that. So they just need your seed phrase just like @hosseinimr93 said, to generate a new wallet
Take note that your password encrypts your wallet file locally, so that someone who has access to your device can't access your fund.
Someone who has access to your seed phrase can use it to generate the same wallet and spend your fund. The thief doesn't need your password at all
After generating the same password, will the new wallet have the same address as the original wallet?