Suggestions for a 4/5 day trip at the end of November

[BugLebowski]

Hi all, myself and the better half usually head off for a city break in Europe this time of year but circumstances this year has meant she can't fly. We're thinking of a long weekend away in the campervan instead. We're in Ireland and since we've spent all summer covering the island here, we'd like to head across the water.

Extortionate ferry costs aside, we can cross either to Fishguard in Wales or Cairnryan in Scotland. The threat of snow in Scotland (and the lack of winter tyres on the van) means I'm thinking about heading towards Devon/Cornwall. I understand it will be a bit deserted out of season but that'll suit us just fine! Any suggestions on open campsites? Were fine with the odd night wild parking but would prefer at least one night in a campsite.