I know with Delgado I had to enforce naps, otherwise he'd just keep going and get overtired. That led to him being more bitey and grumpy which led to both of us being frustrated. He was much better after a nap, even if it was just 45 minutes and then he was awake again and ready to roll
Key rule in raising a puppy - a tired puppy is a well behaved puppy. Make sure he gets lots of exercise before you leave and have lots of toys for your parents to trade off with him to keep his mouth busy. Do you have a flirt pole? It can be a great tool to wear out a puppy and they can be sitting comfortably in a chair while the pup does all the work.
Also stuffed kongs, frozen raw knuckle or marrow bones, beef tendons, etc can all be used to occupy the pup for a bit when they need a break
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - Male GSD - born Jan 26, 2012
Koda & Zazu - 6 year old male cats
Alex - Male Cocker Spaniel (rescue) - RIP Cuddlebug 2007-2010