I did these for about 6 or 7 years when the kids were the right age.
Brilliant, the missus would collect the coupons at work, I'd never buy the Sun, then you'd list where you fancied, and take what you got. We always went last week October and the Easter period, which of course wanders around time wise. For a tenner, you'd get 3 occasionally 4 nights in a caravan park somewhere, a couple of time we got chalets.
I like these places more or less out of season with only a handful about, and it can be fucking freezing....would never have dreamed of going in season.
Always went for a different stretch of Dorset, Devon, North Somerset coastline, to walk a new section of the coast path. Cornwall seemed a bit too far for a short break., more long holiday place for me.
The recall of actual sites is a bit vague, as it was a while ago....think my favourite was Blue Anchor North Somerset, got a chalet for 4 nights, late October and still quite warm....could play on the West Somerset
missus and kids could bugger off to Butlins Minehead, leaving walking to be done in the Brendon Hills.
One October in Swanage, the weather was proper fucking shit, didn't bother me, as walking round by the Tilly Whim caves in a force 8 is the sort of thing that floats my boat....however the kids and missus, didn't fancy it, and with a poor forecast we just wrote it off. Which isn't a problem when you've only paid a tenner.