iPhone in French Polynesia?

How can I use my iPhone in Tahiti without large charges? 

I talked with Verizon support and was told to put my phone in Airplane Mode, then turn on WiFi calling to make calls using WiFi. BUT, WiFi isn't available on an iPhone when it is in Airplane Mode; correct?

I understand about using Airplane Mode while I am traveling so that cellular data does not get used.  But, when I am in a place where free WiFi is available, can I not just use the wifi and make calls using FaceTime Audio (or Facebook Audio) to make my calls without charges?

Trying to understand.

Re: iPhone in French Polynesia?
Contributor - Level 3

Yes, you can turn on wifi while in airplane mode. After putting your iPhone in airplane mode, go to settings>wifi and turn it on. You'll not roam or connect to any cellular service, so you won't get hit with any extra charges.

To put your mind at ease, try it right now, before you even leave the U.S.