If I were going to put in a different Sim card, I would either use either an older cell phone you no longer use, or get a burner phone to put the Sim card in. I know some of the Chinese grocery stores will put a SIM in for you. Then you can make that your vacation phone. I think you can buy how much time you want on that phone. Now it may only work on the dutch side of island, not sure on that. Just make sure you write down all important phone numbers since you would have a different phone. You can go to places and use free wifi, for email messages. I tend not to use my phone so much, but do use an Ipad, but pretty easy to find free wifi to check on email messages. Only a week out for you, have a great time, Teresa.