Standing, I think you ask a good question, actually quite a big one, especially for the many LBSs and their kids if they have them, facing the first holidays without their spouse/father. Any advice to get through those first holidays without falling apart, or even better, having some enjoyable times is extremely helpful.
Since we don't celebrate Thanksgiving here, I'm going to tell you about our first Christmas without H. I still had 2 kids at home, S10 and D17 at the time. After having been used to big, lavish, fun filled Christmases, this first one 6 months after BD, one month after H said he was going to live on the other side of the world and never come back, was an extremely difficult holiday to make happy.
The way my kids and I went about it was to change it up as much as possible. We started a new Christmas Eve tradition that involved going for lunch with S in a food market in the centre of town, buying scampi for dinner, meeting D17 for hot cocoa at the top of a well known department store with an outdoor heated terrace café with views over Florence ( I had never been here before BD), and then driving home to cook the scampi together. This will be our 6th Christmas since BD and we will be carrying out this new tradition. My kids look forward to it.
That first Christmas, we had 4 invites from friends and family to spend the day with them. We didn't feel up to looking happy in public and chose to spend the day by ourselves. It was cosy and filled with love. Since that first Christmas, we have had a single friend and her D over to have lunch with us and spend the day. My kids and my friend's D look forward to this. It's like the family we all no longer have. After a big lunch, we like to fall asleep on the couches whilst watching a movie all together.
New Year's Eve is still a bit of a struggle. My best ones since BD have been when S and I have driven to Rome to spend the night with my cousin and her boys. It's cosy and loud. I would rather have shared a glass of champagne with my H, but being around other people was really the best way for me and my kids to get through and enjoy the holidays.