Trans-Atlantic Travel with iPhone 5s

Afternoon all,

I have been trawling the site trying to get the answer to the questin I have and a few posts have come close but no-one has hit the nail on the head.

In a month or so I will be travelling to the States for a 10 days as part of a series of trips I will be making from my home in the UK to the US. In the past I have just bought a burner phone but hate not having my apps and games and social media things with me on MY own device.

This time I have decided to unlock my phone (done), buy a pre-paid sim and pop it in my phone shortly after arriving in the US

My question is, will this work? I am travelling without my laptop so will not be anywhere near my iTunes or backups until I return home. Is it going to be as simple as pop a new sim in, turn it on and away we go?

Or should I buy the US sim first from eBay (or similar), pop it in the phone and restore my iPhone with all my apps from my iTunes in the UK the night before I fly so that it should all work when I land in the US and put the US sim in?

Just to say, my iPhone is a model A1457 so it should work ok on the US networks