White distilled vinegar. Fill a few small bowls with it and set them in the trailer for a couple days. Smell will be gone.
I had to evacuate during the Rim fire a couple years ago. Luckily, my house was spared, but EVERYTHING smelled like smoke. The vinegar fixed it. I seriously thought we were going to have to throw away all our clothing and bedding. Not to mention carpets and whatnot. Firefighter buddy told me about the vinegar. Works like magic.
And cigarette smoke doesn't hold a candle to smoke from an actual forest fire