This seems like something I should try (again). I could then stuff my PC into a cupboard and work on it wirelessly. What I do not understand is if his keyboard

This seems like something I should try (again). I could then stuff my PC into a cupboard and work on it wirelessly. What I do not understand is if his keyboard and mouse are attached to the laptop or connected wirelessly too. If it is the later, what is the usual maximum range for the mouse/keyboard transceivers (including walls)? Do they generally have low enough latencies to play action video games lag-free? Same applies to wireless display from PC to the headset.