It depends how much you have/want to spend, doesn’t it?
Camping in Northamptonshire probably not a huge amount. A week at Cliveden, much more.
Our cottage (3 bedrooms, terrace overlooking the sea, detached studio for two, big garden, no off road parking though) rents for £1,800 in summer, but we only let to ‘known’ people.
We’ve a pretty 4 bedroom cottage booked in then Lakes for September and are paying £2;800. It has lake frontage and has lots of space, but nothing special.
When on island we spend an average £100 per day on lunches, coffees, takeaway, ice creams, magazines, sundries etc. Then we have a supermarket shop for basics which is about £150 for the week. We usually eat out twice in the week at an extra £150 a time, roughly. Then ferry fares, petrol. We spend about £1000 in total for up to about ten days - we could spend much less but could spend more. We really do tourist attractions, cinema or anything. We don’t want to eat out every day either.
Lakes we’ll spend more as our daughter and husband are joining us. We’ll probably eat out more, buy day spa tickets, stay somewhere on the way up, hire a dinghy or kayaks. I’d not expect to have much change from £2,000 with overnight hotels included.