My mothers house was not quite as bad as yours, but it was bad, and I can fully see the problem where you find some thing which could cost £4000 to repair, it is not the sort of loose change you have in your pocket.
However it is dangerous, there is no way you can continue using it as it is. My son had something similar with his house, and he ended up with extension leads running around the house for 18 months while he installed all the new cables. Mothers house was not that bad, but I did end up with temporary half round trunking on the wall for 6 months before I could do the re-wire.
The idea of temporary lighting plugged into a socket is likely the only way to delay the re-wire while you get the funds required. Be it standard lamps or table lamps, with a very temporary set-up, or trunking with a more lasting set up, it needs thought on how to proceed, if the trunking can be used first with temporary wires and then be latter utilised for a permanent wiring then there will be less waste.