> During the winter time the GPU also doubles as a 300W in-house heater

There could be a service that works in reverse where if someone needs a heater for a few months, they could rent a portable server (e.g. using older repurposed GPUs) with a built-in 5G modem that would run inference on LLM queries. As an incentive perhaps renting itself could be free (or you could earn money?), but you'd still have to pay your electricity bill.