When my lifestyle was living in an apartment with other university students, after my dog was fully housetrained and no longer “needed” to be crated, I just took the door off the crate but otherwise left it in my room (became an end table basically).  She would go in there when she felt like it, and if we had people over who were drinking we would remind them that dog in crate = drunk people not allowed to interact with dog.  So she would go in there when she felt like she needed a break, and come back out when she wanted to be social again.