What time to leave London to get to flight in Gatwick?

Arrivve three hours before for an international flight which takes you to 7.45am, then two hours drive from Earls Ct to Gatwick which takes you to 5.45am.

If the airline says be at check-in 3 hours in advance, they mean 3 hours. That is normal for intercontinental flights. European flights are normally 1-2 hours.

What time do you think we need to tell the driver to pick us up to make it to Gatwick in time?

The car company is more likely to be familiar with traffic conditions and how long it takes that time on a Monday morning. When you book the car, say you need to be at Gatwick at 07:45 and ask them to suggest a pick-up time.

Would it be better to take the Gatwick express for time or is the driver the best we can hope for?

Have you checked what times the trains run that early? You will need to get a taxi or driver to take you to Victoria,or go by Tube, buy tickets, find train platform get on train, get to Gatwick, get off train, haul self and baggage from station to terminal etc. If you leave from South Terminal, that is it. Otherwise you have to get to North terminal by the shuttle which does involve more walking to reach that. Probably by the time you have done all that it will make little if any difference in time spent. Personally I would rather spend the last night at one of the airport hotels.

yup....driver it is.......We thought of spending the last night near the airport but we would need to check out by 10 the day before and then store our luggage.....Nope, Driver it is.

Thank you all for making my decision concrete.

72 year old Mum, who will be tired after 34 days on the road = take a car.

We flew From Gatwick to Toronto in July.. yep to the 3 hours.. From Toronto, we do 2 hours for flights to the US but do 3 for international flights which is also what Pearson recommends.