This coming Sunday at church I have been asked to run trains for the kids while our yearly Christmas special is going on. There are two Christmas trees in the church foyer that I placed track around. Standard gauge on one side and O-Gauge on the other. My plan is to run the MTH Ives National Limited set and the Lionel scale Polar Express. I have never run any train for 4 hours straight before. Should I bring additional engines to split the time? Do I need to be concerned about overheating?