Good question Tony,
I've run HO Christmas trains since 1974. Before Bachmann's EZ track and knuckle couplers they ran until they derailed.
I picked up a 2004 Athearn Coca Cola Christmas DC set with EZ track and Knuckle couplers and ran that set until 2011. I would run it for a few minutes to as much as 12 hours a day continuously off and on under the Christmas tree during the holiday season. I never once lubed it, all I did was keep it clean. The last year she ran, 2011 she began to sequel like a stuck pig after new years.
The next year, 2012 my daughter bought me a Lionel Polar Express set. (my first steam engine) It came with a manual and instructions on maintence so I oil and lube it every year before setting it up. It runs for hours on end off and on throughout the holiday season. Last year one of the linkages broke, but was easily repaired and is running now as I am typing this reply.
I have a Bachmann DCC GP38-2 pulling a consist of 6 cars, Tyco and Life-Like from the 70s under my little Christmas tree on my small HO layout. The cars have been upgraded with Bachmann 33" steel wheels and Life-Like Scene Master knuckle couplers using the original plastic trucks. It ran trouble free for over 16 hours on Christmas day.
Throughout the holiday season my trains can run for hundreds of hours. If one wears out I will restore it or buy another one. So far I have had little trouble with them. I love to hear and see my trains running. Restoration or replacements will be money well spent in my mind.
Merry Christmas!