DS (26) isn't bothered by Christmas , he'll emerge for dinner ( he's the only non vegetarian except the cats )
DD and I are Full On Christmas
DH just goes along with it 
Last year DH,DD and I went on a short cruise ( Christmas Markets ) leaving DS to house sit/cat sit
This year we're going on a UK City Break .
So we'll have our trip out and enjoy early festivities .
Then on Christmas Eve/Christmas Day/Boxing Day it is far more relaxed.
I do like the 6am supermarket trip for last minute things in Christmas Eve though.
No actual let downs . I don;t buy a turkey , couple of chicken breasts for DS , plain roasted and the cats get share.
I only make puddings that can either keep in the fridge or freezer another day .
We have plans for the weekends up till the day itself , nothing full on.
DD has a Dec 1st Box of things she wants through December ( make up, nail polish, skin care , her pyjamas ) so she gets good use .
Then her presents on the day are jeans or training shoes type . (GHD styling brush this year )
Don;t get The Twitch
Don;t buy too much chocolate
Don;t try and buy DS anything other than cash ( though I di buy his Dec 1st socks/underwear/loungwear for the year ) and some toiletries
Don;t imagine how nice a tree would be , the cats would wreck it
I am trying to find a nice Christmas cake but only I eat it so I wasn;t going to bother . But I really want one . So I;m going to bake one . (I do a very light one , no spices , caster sugar . I do my own marzipan and icing ) I will make 2 small ones and store one ./ ice one .
I have tried some shop ones and they really aren;t nice