That's gonna be quite challenging considering he just recently broke his arm and can't use one of his hands.
I don't know to what extent said arm is restrained. Sometimes it is not good for it to be there and extended for 5 hours to play a game but can be moved for 20 minutes to sort something, else it might also be that the plastic wrap comes over the thumb and makes it hard to hold a controller.
At the same time it might take a bit longer but I have put together a few wired items one handed, upside down and in the dark. While two hands, or indeed three hands, is preferable for a lot of electronics fiddling you can still clamp things to the bench, change to a driver, unscrew, insert stripped wire, possibly make efforts to hold wire in, change back to driver and tighten. Would I do that for a 60 wire setup I am charging for? Probably not. Would I do that for a max 6 wire foot pedal setup, all while knowing it will be useful to me personally over the coming weeks and weeks of boredom? You bet.
Equally while getting someone to play a game for you might be a bit decadent you can probably make doe eyes and gingerly lift the busted arm (possibly with a few false starts) at someone that knows how to solder/turn a screwdriver and sort it that way.
Forgot to mention last time. If you are playing via emulation you might also be able to buy a wii joycon adapter (or a whole wiimote + a bluetooth adapter if necessary). I don't know how easy it will be to sort their internal motion/tilt sensors but they hold well in a hand (holding a controller for hours in one hand with gravity making a notable torque, have an analogue, a few buttons and possibly even a few premade scripts for things.