I’ve been editing with a 15″ mbpr (early 2013) for a couple of years now and it works just fine. I use external thunderbolt storage and external usb3 cache drives and a thunderbolt monitor. I still prefer my late 2013 iMac with the same storage options though. IMac at home, MacBook at the office.
One big advantage of the iMac is you can’t spill coffee on it. I’ll be getting a new MacBook next week…