Background: I am a Jewish convert; most of my family is Protestant and Catholic.
My family used to have a two-part Christmas - Home Christmas and Grandparents' Christmas. Christmas Day was pretty laid-back - my parents, brother, and I would have muffins and open presents in the morning in our PJs.
We rarely had anyone over. My mom doesn't like hosting parties. Christmas lunch/dinner were usually simple things - leftover Thai food, sandwiches, nachos.
On the 26th, we got up early and drove from New England to Central Pennsylvania. When I was a little girl, both sets of my grandparents were still alive. They lived in the same town, so we'd visit my dad's parents during the day, then go to my mom's parents in the evening.