From what I’ve read you can’t extend EV cables legally. My car would also be too far away for the 8m cable so I specified I wanted the Ohme ePod on my order (which so far I have no chance of them fitting!) which doesn’t have a fixed/tethered cable.
If I manage to get the charger fitted I’ll buy a 10m cable, you can get longer. This company do them up to 20m.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!