My ceremony begins at 6:30pm (a requirement of the venue). It will be short - probably like 15-20 minutes and then I plan to have a cocktail hour and then dinner at the reception (same location). I am concerned however that even with food at the cocktail hour, that serving dinner at 7:45 or 8:00pm might be too late for guests. Does this sound too late? Should I shorten the cocktail "hour"?