I had a week down in Cornwall at the end of July and was suprised how quiet it was - much quieter than usual (I go every year). The streets in the towns were a little busier, but mainly due to restricted numbers allowed in the shops. St Ives and Padstow had a fraction of the numbers of previous years, and Boscastle car park was 3/4 empty (whereas you're usually lucky to find a space).
Going again next week, so will be interesting to see if it's changed.