Computer to Computer Video Calls

Your biggest challenge will be finding the necessary internet connection. You can provide your own so that when you are in an area with good 4G service you will have enough speed to make a reasonable video chat. Some campground wifi systems will work but it's really a tossup as to yes or no. You might be able to do the chat from McDonald's or Starbucks (or many other) as their connections are usually pretty good.
If you use your cellular connection to get on the internet your monthly data will be limited but as long as this is only something you do a couple of times a month (and not for hours) it would likely not have much of an impact on your monthly data limits.
I will let other just in with the various services as I have only done a few Skype calls and have never tried any others.

We just finished 21 months on the road on the eastern half of the US. We used skype to stay in touch with family and friends, and now use it to stay in touch with the people we met while out east. Works good and is free.

It would be helpful to know why computer you are using. A lot will depend upon your connection and carrier If using WiFi , hard to beat Apple's FaceTime for ease of use and dependability.

Using iPads on both ends I have has great success. As easy as selecting a phone number and making a call

Good luck.