How to help baby nap when your out places?

What do you ladies do to help baby nap when you are out places like someone else's home. My 10 week old little guy naps fine if we're home, but if I'm out somewhere he fights them and is very cranky because he is over tired. I'm kind of dreading Thanksgiving because I'm worrying about how her will be. Thinking about bringing his favorite swing over to my families just in case he won't nap. Any other ideas?