Redocs,
I am having the same issue with my unit that I purchased a little over 5 days ago. I have tried all the usual fixes ie dirver update, power setting, ect. ect. and frankly I'm tired of screwing around with this crap. I echo your thoughts on the fact that the Dell XPS 12 is not a budget level laptop and its not unreasonable to expect it to work properly out of the box.
Great New! I have found a solution.
Step 1.
Return the piece of crap laptop.
Step 2.
Cancel your Dell account
Step 3.
Promise yourself that you'll never do business with a company that knowingly ships a product with a major defect / design flaw.
Step 4.
Buy a Lenovo, Asus or Samsung laptop (you can add Apple to this list of OEMs making reliable machines if you aren't looking for a windows product).
Good Luck.