House Guests and Introverts

My mother-in-law has been staying with us for several days. She's a sweet woman, and she lives several hours away so my husband, K, doesn't get to see her as often as he'd like, so we were happy to have her come visit.

The problem with visitors for us is that our house is tiny, so any guest has to either sleep on the couch or on an air mattress in the office (a room so small there's barely enough room for at twin-sized mattress). This is fine for a night or two, but extended stays get uncomfortable for the guest.

I'm also an introvert, and I regularly need time and space away from other people. Regardless of how much I love my family or friend who is visiting, I get overwhelmed with constant talking and entertaining if I don't get a break. Some people get it, and are also happy to have some time to themselves. My best friend is like me, and whenever she and I visit each other neither of us has any compunction about saying, "I love you, but let's go be in separate rooms for a little while" after a long day. 

Other folks, like my husband and his mother, are very extroverted and enjoy being around other people as much as possible--and many don't understand why someone else would find so much socializing to be tiring. It can be a challenge to steal away for a few quiet moments alone without them misunderstanding what it means or taking it personally. I admit that yesterday I found myself running errands that weren't urgent, just so I could be in the car by myself for a bit. I felt guilty about it, but it also felt good to be alone for a bit.

Question for other introverts out there: how do you survive house guests? What tips do you have for getting the alone time that you need?