Thanks for a useful comment.
Do you reckon the 4bit quantized Vicuna just won't do here? https://huggingface.co/anon8231489123/vicuna-13b-GPTQ-4bit-1...
I think with this everything OpenAI demonstrated ~5 weeks ago has been recreated by actually-open AI. Even if it runs much much slower on prosumer hardware and with less good results at least it is de-magicked.