Lots of really good toddler friendly cottages reviewed on this site www.kiddieholidays.co.uk/. Have you ever tried the Isle of Wight? Away Resorts are running toddler breaks there in June and you could stay in a luxury lodge, which are really roomy. It has the beach, pool, soft play and playgrounds. We enjoyed our stay there. www.awayresorts.co.uk/little-campers/ Hope you find something.