I have a 13" Macbook Air, try to travel as much as possible. At home I have a single 27" 4k screen. Both at home and remote I work with just one screen so I'm able to keep my workflow exactly the same. Honestly, I think my productivity on my 13" does drop somewhat, but nowhere near the 50%. I would say I lose 10% of my productivity. For me that 10% is totally worth it to be able to work remotely and travel more.