Wedding ceremony 11am - only time available!!!

I am just wanting some help on the wedding itinerary planning as we have heard back from the Registrars that the only time available on our date is 11am!!! I am a bit panicky as to how we will manage the day from here as the ceremony and reception are at the same venue. We were not anticipating the evening guests would come until 7ish so it feels like a long day for people but do you think this would work with photos, drinks etc before wedding breakfast and then a small break before the evening? Our flower girls and page boy are all under 5 so will be up at the crack of dawn - it's more a worry about the gap between the wedding breakfast and the evening I am struggling to think about?