What is the largest monitor I can get for a MacBook Pro 15" mid 2015?

I recently bought a MacBook Pro 15" mid 2015. What is the largest monitor I can hook up to it without the computer overheating? I was eyeing a Dell Ultrawide U3818DW, but this user told me it does not work with it. So I am now considering a ASUS 32 " 4K Ultra HD ProArt Professional Monitor [PA328Q] IPS (preferred choice) or a ASUS PB328Q 32" WQHD 2560x1440 4ms DisplayPort HDMI DVI Eye Care Monitor. Would they work with the Macbook 2015? I would use them mostly in OS X but also in Windows 10 Bootcamp or with Paralleles 14. The priority is to use with Mac OS X though. Thank you in advance!