UPDATE: SCS Have now released the beta of 1.16x this beta removes the xmas cargo. Since not everyone uses the betas I will leave the mod up until 1.16 becomes public.
Please remember to remove the mod when you update to 1.16x.
With Christmas long over and the Xmas Event finished, I’ve seen many people complain about the trailers still being present in game.
The No More Xmas mod (bottom of the other mods page) sets the probability coef to zero stopping the cargo from spawning.
Any current jobs will remain in the job list until the offer expires, but no new gift jobs should spawn.
Once SCS release the next game update (which I believe will be for the DLC compatibility) they will likely remove the trailers or lower the prob coef. In the mean time this mod will do it for you. I have left it completely unlocked so you can alter the coef for yourself to suit your needs.