Turning big articulated locomotives was, I suppose, a huge pain in the neck and done as seldom as possible--but if you really had to turn the unit around, and your turntable wasn't large enough to fit the engine and tender, off it came, amidst much screaming, wailing and gnashing of teeth. Ideally a facility big enough to store big engines like that would have a suitable turntable, though. They weren't common if it wasn't a facility intended for such use--for the same reason as we modelers face: a really big turntable is expensive and a space hog!
I do know that the enginehouse at Dunsmuir, CA had a couple of sheds alongside the roundhouse specifically for the big articulated locomotives, because even with the Dunsmuir roundhouse's later expansion it wasn't big enough to fit big AC units on the turntable!
So, in response to an earlier comment, they parked the tender on a siding until it was the tender's turn to be turned around.