When it comes to phone connectivity the phone is one half of it and the tower that surround you and frequency will be the other half of it. So if you are traveling for work some areas may not have the same coverage as others because of this. Having a phone with the most amount of frequency support built into them is going to give the best connection options as you move from place to place.
The model of Samsung Galaxy S7 Edge that has all the frequencies to maximize connection is the G935F or theG935T. The G935F version would not pick up the WiFi calling feature unless you put on a custom ROM on to it but the G935T should. What I might suggest though is using our Personal Shopper program to locate the phone for you. It's a program that we have where a team searches online for phones compatible based on your specifications. They'll send you some links to choose from and can help make sure that you get the right phone for your needs. They're still here over the holidays and all you have to do is fill out this form to have them start the process