I have heard that there are apps out there which would enable this but you would have to jailbreak you phone. This voids the warranty.
Are you aware that, as an ATT acct user that you are entitled to free wifi at Starbucks and any McDonalds which offer wifi (a lot do, but some don’t, depends on franchise owner).
There are also apps in the regular app store which will locate Starbucks and McDonalds near any location where you are traveling.
However, you can’t just stroll in and expect any of the employees to get you connected. I haven’t done it in about a year, but it involved calling in and getting a text mssg back which gives you a code.
Call 800 MYIPHONE and persist until you get one of the Apple techs who have done this themselves who can walk you through it. Some of them are just as clueless as the McDs employees. Just get one who has actually done it.
This code can also be used to get your comp online as well ad your iPhone or even both.
I’d suggest a trial run before you leave on your trip. Also do not delete the txt mssg. The code needs to be renewed every 24 hrs, but the mssg also contains the original info for you to just click on to get a new code.
It’s a little involved and not well known, but hey, it’s FREE.
Good Luck.