It is enough time to do it all, also they can extend it for u. I think my 1/2 hour actually was an hour because nobody was getting married right after me. Also my friend had a cocktail hour and hers was strictly 1/2 hour, cause they had people getting married right after them. I guess it is just luck of the draw. Also they usually have certain spots for your cocktail hour, but you might be able to ask for a different spot, depends on ur onsite WC. Good Luck!