I think if you need the extra space you'd better off with a dual monitor setup. A 29" screen isn't that big, and by the time you've split that up you may find yourself scrolling a lot or zooming a lot, either of which might get frustrating after a while. A couple of smaller screens would actually give you more room, however that does rely on your laptop having multiple outputs.
If it doesn't, then this seems like a pretty decent compromise and I reckon you should try it before I commit to buying one myself