BTW, One of the things that smartthings allows you to do that Iris does not is to create virtual devices.
You can create virtual contact and motion sensors that will also look like switches to SmartThings. Then you can turn those switches on and off anyway you want.
Tell the family that any object you want is a “Santa Sensor” – the elf on the shelf, a particular ornament on the Christmas tree, a particular stick up decoration on the window.
And then you can create automations which will cause those “sensors” to trigger based on whatever you want: Time of day, someone leaving the house, a Light going off in the upstairs bathroom—any event that smartthings can detect. 
You’ll get the notifications on your phone. You could look at the history for the sensor. You can have other events happen like an RGBW light turn red or green, or music or sound play. Or have echo say a particular phrase.
So really, you’re only limited by your imagination if you want to create your own “Santa tracker“ in your own house. . 
The following FAQ discusses using virtual sensors to trigger Echo routines, but you can use the same DTH without a voice assistant just to trigger other events like lights or starting the toy train or whatever.