Our devices were seeming to receive calls at random too... but here is what I have figured out so far.
1) Each device you want to receive incoming calls has to be 'signed in' (e.g. if your location, IP address, etc, has changed because you're travelling you may need to go to the Facetime/preferences, and sign in again. (that should get the laptop receiving)
2) Each device can (in the settings) turn facetime on or off (on the iPhone it's just Settings, scroll down to FaceTime, select it, and set the slider to on or off, on the computer it is on the main menu bar under FaceTime and you select 'Turn FaceTime On' and 'Turn Facetime Off'.
If you turn Facetime off on your home computer before you leave your wife won't have to listen to it ringing in the next room, and as long as once you've got your new IP from the hotel wi-fi, and you 'sign in' each time you are somewhere new (on bar on the right side of facetime) that should do the trick. (or at least that's how we got the Apple devices we have sorted out.)
Hope this helps!