I've been thinking about doing that but what do you do about the monitor? I imagine you're not bringing one with you (maybe you're moving one around your home), but what happens when you move to work in other places? Customers, friend's places, restaurants, etc.

I use the m1 air for web development and the 16:10 aspect ratio combined with the retina screen and the gestures to easily swipe between full screen applications makes it feel less cramped than the 14 inch 1080p thinkpad it replaced. I never feel the need to hook it up to external displays. Of course, YMMV.