I am a single mother with primary custody, this happens rarely--I don't have kids, work, or obligations to be anywhere else. I decompress a little and tackle a list of things I want to get done. If its for four hours, I might use all four to decompress and just "veg" out.
If it was a surprise occurrence...
I think what it'd look like is me pacing around figuring out what to do.... Then deciding I need to unwind, finding a way to get comfortable. Convincing myself the chores can wait, allowing thoughts flow through my head, coming to peace, then doing something I enjoy or need/want to accomplish. I do enjoy "me" time, but sometimes its such a foreign concept I always feel as though I have to fill those hours doing something, anything for anyone and everyone else.
A good way for me to decompress is a long bike ride, run, or workout. :) It clears my mind!
My best rule when this occurs, is to put my phone in airplane mode! ;)
Phone on airplane mode is a great idea!!
So, I have to admit that when I'm in the house alone, I go for cleaning first. If there is time left over, then I sit and watch a movie (or start one to finish later).
And if I have more than 4 hours, I go for cleaning and then a project and THEN a movie. But often I miss the movie part with this because projects take longer often than I anticipate.
My friends think I'm nuts for this. My husband does too. But it is SO much better to relax when I feel the house is in good shape than not. :>)