You might wait a while a) to get good enough weather to get down there and b) to get weather good enough to get back...
I used to fly a Cessna Crusader into a disused airfield in Cornwall every week for 9 months on a commercial basis.
Yes you are correct that Cornwall is prone to fog and low cloud. We often had to take an alternative into exeter.
If the weather is stable and good you cannot beat that run
Pace