What you describe sounds lovely op but it is as seen through a child's eyes. You don't at that age think of the work that goes on hosting and creating such a lovely time. (It reminds me of Monica Dickens' Marianna, where Mary's memories of holidays at her grandparents' house didn't include the huge adult rows over the kids and the like)
We didn't have Christmases like yours. Still in the 70s, but my father had died, his family went NC with us (I didn't realise I actually had other cousins!), my gran was widowed so only one grandparent, my mum's sister and her family lived in another part of the UK, mum and stepfather not good hosts, we didn't have spare cash, etc. So altogether a different experience. Your childhood Christmases look like the ones in supermarket TV adverts!
You have been very lucky that you had that, and you have those memories to look back on.
One atrocious memory I have is the Christmas right after my mum's divorce came through and SF finally fucked off. We had our Christmas dinner laid out on the table, my mum looked at it and said "This is greed, not need". FFS. A) She chose it all and cooked it b) that was the sort of miseryguts comment my SF used to make, and we hoped to be finally free of that sort of shit, and c) it was actually rather meagre by ordinary standards, it's not like the table was groaning with peacocks' tongues and roast swan. There weren't even pigs in blankets FGS!
She's mellowed a bit but I still feel happier if we don't see her, she's harder work than I'd like at Christmas.