This is very likely hardware issue.
I had similar problems twice with new hardware, once with new motherboard and once with new laptop. When you buy new hardware you expect it to fly, and when it starts freezing - after 4th or 5th reboot you can be ready to throw it through the window. :)
Motherboard problem was solved with new BIOS firmware, laptop problem was solved in service with change of faulty memory.
If you have time and energy, and spare partition on hard disk (or spare external drive), you can try installing Windows, as problem may be in drivers, it does not need to be faulty hardware.
If Windows are working OK after two or three days, than you can try to disable in BIOS hardware which can be disabled (like graphic card), and you can try using other kernel version (newer or older), or disable some drivers.
I'm aware that such tasks are complicated, but deducing/debugging hardware problems is job for experienced users or professionals.
Edit: Recent Dell laptops are quite Linux friendly (they even had series of XPS's or Inspirons labeled Linux inside or something like that), so recent kernel & distribution (Ubuntu 1604 was published last month) and fresh install should work without problems. I know this is not information that you are happy to read, but as unlikely it can seem (faulty new hardware), it is possibility which should not be discarded without thought.
I write this not to scare you, but to hasten solving of your problem, as I quite well remember how I miserably felt when I was in similar situation.