We have been at WDW for Christmas several times -- twice when DD was little (6-7 years old), and four times when she was 13+. What motivated our first trip was that my father had passed away in September, and I just couldn't face a Christmas at home without him yet...so I proposed it to the family and they liked the idea...and we all enjoyed it so much we returned for Christmas the very next year!
I was worried about presents and Santa being able to find us too (and so was my daughter). So the first thing we did was to have DD write a letter to Santa in early December explaining where we'd be this year, and asking him if he'd please bring her present to WDW instead of our house (Santa gives one present, and mom and dad give the rest in our house). We mailed it in one of those "letters to Santa" boxes at Macy's. Then we had our DD pick out a mini-tree (I'm talking maybe 12-18" tall and skinny), some string lights, and a few strategically sized/shaped decorations that we could put up in our room. The final thing we did was discuss that for our presents to each other, we would just bring 1 or 2 small ones, and then the rest would be waiting for us when we got home (and since we got home on the 27th, waiting 2 extra days wasn't a big deal).
That first year, Santa brought our DD an American Girl doll, which "he" strategically and carefully packed in its box in a carry on suitcase, hidden under some clothes
. Other than that one, the gifts we chose to bring with us were small in size, and the rest were left at home. Our DD got a kick out of bringing our little Christmas tree in her own suitcase, and setting it up and decorating the room all by herself (winning!). At 19, she still has that little tree, and set it up in her college dorm room this year.
We also allowed our DD to choose a souvenir on the day after Christmas so she'd have that to look forward to as well (instead of focusing on all her presents that were at home waiting for her). I have also heard of some people shopping for gifts while they're at WDW as they notice their family admiring certain items, and I think it's a great idea too.
One of the accidental discoveries we made that first year was the "x days 'til Christmas" countdown sign near the park entry for MK. On the first day, we had our DD pose for a photo near it, and it made such a cute shot that we came back every day and did it. The expression on her face when it was finally 1 day 'til Christmas is priceless, and DH and I cherish that photo! We did the same thing the next year, and our DD was even game to pose in front of it for our last Christmas trip in 2019.
I honestly don't remember if the resort did anything special for Christmas day, but I've always made favorite or extra-special ADRs for Christmas eve dinner, Christmas brunch, and Christmas dinner...and in the past few years, we've also done the Christmas eve Candlelight processional (gives me chills just thinking about it!), brunch at Ale & Compass, dinner at Minnie's holiday dine at H&V (though we love LTT for it as well), and JBJB on Christmas night.
Honestly, despite the crowds, we think Christmas at WDW is the best thing ever. No cooking, no cleaning, so much holiday cheer everywhere with the decorations and music...it's just the absolute best! And another win -- there aren't as many leftovers sitting around, so I don't gain any weight!
Sorry this is such a long post...but we were so sad last year when we had to cancel our Christmas trip due to Covid, and I actually just booked our Christmas trip for 2021 yesterday, so all of this is very much at the forefront of my mind! Hope this was helpful to you in some way, and good luck with your decision.