@OrigamiOwls
The idea of a "big family Christmas" or "only children are lonely" is a social construct and not something people should let rule their lives.
Fully agree with that. It's certainly different, but not necessarily better or worse than a "traditional" setup.
My DS only saw OH and myself and OH's mother yesterday. A very quiet day. That's how it's been for a few years now. DS is an only child. My brother shows no interest in any of us and has no children. OH's sister shows no interest in him and her children life their own lives and show little interest in her, let alone us (they were both "troubled" teenagers in different ways).
We'd expected our DS and his cousins to be "close" to an extent, as whilst they were older, there wasn't much of an age difference, i.e. 2 & 4 years, but even when we went to their house for Xmas or birthdays etc., they'd basically ignore him or would be in their rooms (or out) with their friends. They didn't go to the same schools either, so there was no other contact, and they lived too far away to "pop around" between our houses.
We often have "the conversation" with DS about lack of a sibling, but he's not bothered. He knows he's missed out in some ways, but also that he's gained in others. He's not shy about complaining about lots of other things in life, so I believe him when he says he's not that bothered about being an only one and not having close-by cousins, but what he's never had, he doesn't know what he's missing!
I do think that what's more important is living close by - i.e. the cousins being able to visit eachother themselves, i.e. walking or cycling or whatever, or at least going to the same school. When the "connection" has to be pre-organised, including travel/lifts, etc., and often at "big" occasions like Xmas, birthdays, etc., the "cousins" just don't get time to themselves to do their own thing as it's dominated by the adults, so they can't just "sit and chill" as it were on their own, so it just doesn't work as well as it would if they were living on the next street and had their freedom.