2008 Vauxhall Corsa engine warning light comes on when its cold

On the first cold day in December my engine warning light came on and after driving about 5 minutes the car would lose power and would struggle to accelerate. I phoned Vauxhall and took the car to them, when i drove the car there i experienced no problems, the garage said it was a problem with the throttle and replaced it, i had no problems with the car but after 3 days my wife was driving it home late and the problem accured again, took it back to Vauxhall again and it took them 5 days to find out what was wrong with it as they would try something drive it in the morning and then discovered the problem wasn't fixed. in the end they replaced 5 wires which they believed to be corroded, again i experienced no problems then 5 days later it happened again, now Vauxhall are on about replacing the whole loom which means my car would be off the road for 10 weeks and cost me £3000, this is not an option so what i do now is start the car in the morning limp it for 10mins turn the engine off and on, off and on and eventually the light does not come back on, at this point i can drive as much as i want, hundreds of miles without experiencing the problem again until the following morning and start the same rigmarole all over again. please help.