When was the last time you were sure that your friends' plan would get executed?
There is always a chance that someone will have something else to do at the last moment, and you will have to cancel your tickets.
Well, you run into the risk of most of your booking amount getting deducted as a cancellation penalty.
But as you have the Sun country change date on a ticket option.
You will very easily change the date and will not have to cancel the flight tickets.
For more information- https://cheapairlinesfares.com/blog/sun-country-airlines-flight-change-and-upgrade/