If only it could work without occupying a GPIO pin pair... I use a DVB-T2 TV hat and it doesn't leave any pins spare :-( So I'm going to buy a USB fan, power

If only it could work without occupying a GPIO pin pair... I use a DVB-T2 TV hat and it doesn't leave any pins spare :-( So I'm going to buy a USB fan, power it from a separate power supply and and glue it to a fan-less case vent holes. This isn't going to look nearly as pretty. What I would like to have is a fan-cooled case with a circuitry which would take a high-power laptop-grade USB-C charger as an input and split that power between the Pi and the fan. Perhaps it could also split the USB-C port into a power input port and an actual extra USB port.