Our "S" Gauge round the room trainset once took up the entire dining room floor starting the day after Thanksgiving, and finally came down in February.
My "HO" round the room trainset took up the entire living room floor, and went up on Thanksgiving, and didn't come down until May.
It took 3 whole minutes for a 36 car train to cycle around the room.
The Christmas tree stand was drywall screwed down to the floor, as trains kept derailing under it, as the twee was constantly being toppled over in the re-railing process