You don't need to do anything except perhaps wait a bit longer for the kettle to boil !
On many(most) UK sites you will be lucky to get 220V in the early season when everyone is using electric heaters etc.We went to France in August one time and several on the rally thought that their battery chargers weren't working .BUT if they were checked in the middle of the night then they showed a charge when fewer people were drawing on the system.Hope that helps
Voltage is not the issue bt amperage is. Many Irish sites only have 5amp supply so electric kettles etc generally out of the question. Check this carefully on the site description and go equipped accordingly