Getting engaged or married means you will now be a part of two different families and have to coordinate how you will celebrate the holidays while trying to make everyone happy.
My fiancé and I have been together for five years and at the start of our relationship we would do our own thing with our families because we didn’t want to give our family traditions up. As the years went on and our relationship became more serious, we decided we wanted to see each other more for the holidays whether it meant spending time with his family or my family.
I think it is important to come up with a solution that is fair to both sides. We have lucked out the past few years for Thanksgiving because my family has done stuff earlier in the day and his family had dinner at night for Thanksgiving so we were able to do both. (It helps that we don't have to travel too far to visit either family.)
Christmas also became easy because my big family celebration is Christmas Eve where his family celebrates on Christmas Day. As for Easter, we go to church with his family in the morning and then brunch with my family after.
We have managed to fit everything in or come up with an alternative day to celebrate if we can’t, but it may be more difficult for others. You may have family out of town or other family with hectic schedules who can only do things at certain times. In this scenario, it may be best to take turns, celebrating one holiday with one side of the family but then celebrating the next holiday with the other side.
Hopefully, it will get easier over time I’m sure but can be difficult at first. If you really want to see everyone, you can also host a party yourself so that you’re guaranteed to see all the family members who can make it to your place for a new tradition.