I've tried the "roving" lifestyle and I have to say, dual monitors are hugely helpful when developing. We took a downgrade by losing offices for open spaces. I hope we don't take another downgrade by losing our desks too.
Recently I switched to a single 38" ultrawide (a xr382cqk) and I've taken down the second monitor.
Windows and OS X both have good enough tiling that I can use the single monitor without the distraction of bezels, and there's much less ceremony to hooking up one monitor
I think the same thing would work with a ~40" TV, and I e seen people do it, I just prefer the space efficiency of the ultrawide
At my last employer I was a roaming employee. No desk. Just a file drawer. I was not a dev then. But I hated it. I had to wander 4 buildings to find space to work. I hated it.