Overnight caravan stops France and Spain - Winter

RHM

I'm trying to find a list of overnight caravan stops between e.g Calais and Southern Spain that are open in February. They only have to be open, secure and functional (turn up, wind down, roll-up & move on next
day). Not interested in 'holiday sites' with loads of fancy facilities. Gordon Bennett !!! what a rigmarole trying to find this info. Can anyone HELP
PLEASE?