After Wedding Celebration help!!

AmberNJ14

My fiance and I are getting married on the beach with just parents and siblings. We are then treating them to a dinner and a few hours of open bar. Dinner is being held at our hotel and we can enjoy time together after dinner at the pool, bar, terrace etc. My question comes in here. Because we arent inviting a large amout of people to the wedding we were wondering if we should invite people to celebrate with us but after dinner. Especially because my fiance has family from the beach area. Is it rude to invite them after dinner? Would it be okay to have a cash bar at this point also? We would be getting married around 11 am, then having dinner early, and then maybe inviting friends to celebrate with us around 5 or 6pm.. Any suggestions?