A slightly flippant reply, I know - but -
If you've only 2 days in total, IMO it's not worth it going all that way to an out-on-a-limb part of England. If you had 4 days in total then it's still barely worth all that travel to Cornwall and back.
I was assuming the flight home was on day 3 , but if not then it’s absolutely a non-starter.
Two days is just not enough. Where is your tour going. Perhaps we can suggest somewhere more suitable in the time you have. For example, the South Downs national park is a much better fit with a Gatwick departure.Edited: 30 March 2018, 19:43
Thanks for your honesty