That is the thing with trips and kids... they don't always get back to normal after returning. And while away, their sleep/nap routines are different and they get thrown off.
For us, for this reason, we didn't travel until my firstborn, my daughter, was about 2 years old. But I co-slept, while away and at home, so it was not anything "out of the ordinary" for her. Even while on our trip, I would go back to the hotel room at her usual "nap" times, and then at her regular bedtime... and just kept the consistency the same and the same "routine" as what we would do at home. So this helped.
When you go on trips, with a young baby/child... it is always beneficial to KEEP to the same schedule/routine as when at home. For us, we went according the the needs/schedule of our child... instead of making our girl put up with ours. IN THE LONG RUN... once you get home, it is a lot less painful and frustrating for you, and them.
Also, kids this age won't remember perfectly how it was before the trip... all they know is the comfort and what "recently" was. So this is what they NOW expect.
All I can think of, is he is having to "change" and transition, again, now that he is home. If he is in his own room... (in a crib?), then you can slowly just go back to the same routine you used to do... it will be about re-teaching him. And he is probably missing the closeness of co-sleeping with you both. So there is a "separation anxiety" involved too. It's a hard nut to crack... but, his "consistency" has been lost so to speak... and then at Christmas on that trip, it will "change" again.
I don't know that he will go back to his sleep routine, again, right now... it may take as long as the next trip... but then, he will have to change again.
You could, on your next trip, allow him to sleep in the same room as you...but on the floor, on a mattress or something. That way he is in his "own bed" so to speak... but still around you... and in the same room... this MIGHT make him feel more secure... and able to feel comfort.
You could even do this at home... to transition him back to his "own" bed. Both my kids do this... we are co-sleepers or we have a futon mattress on the floor in our room and the kids sleep there too.
And too, maybe he is also, going through other things at the same time... maybe teething, developmental changes, growth spurts where they get more hungry etc. Babies/kids often have MANY things on their plate at the same time. It is hardly just a "single" issue at one time...
The thing is, there is such a quick turnaround for him to adjust to- ie: just getting back from a trip, having to adjust to sleeping again at home, then going on another trip soon again. The jet lag etc. That's a lot for a baby.
Co-sleeping, if you are not against it, would be the "easiest" way to get him to sleep...
Not all kids/babies are able to just change and readjust to changes. If he is the type that likes "routine" and responds best to that ... then, any changes to that will throw him off. Each child is different. Some kids can adjust no problem and others can't. Just as adults.
It will take time... or, you could just co-sleep with him for now until your next trip... go on your Christmas trip... THEN when you come back from that trip, spend all the time you need to get him back on track at that time. Because, expecting him to get back on track now before your Christmas trip and then going on another trip right after that may be too much for him to handle right now. Too much pressure on him and you. And, it would just be futile. You can either go through it now, twice... or just once after you come back from your Christmas trip. Know what I mean?
For your son, he had to "change" when he got to your destination for Thanksgiving, then again when he got home from that trip, then he has to "change" again when he goes on the Christmas trip and that locale... then change "back to normal" AGAIN when he comes home from that trip. That is 4 times of readjustment for him, in a quick succession. Hmmm. Not easy for a baby. Quick turnaround for a little one. Allow him ALL the time he needs to "change" back into a regularity at home... in terms of sleeping and everything, once you get back from your Christmas trip.
All the best,
Susan