Firstly Mazal Tov I also saw it on Only Simchas and was waiting for the announcement on the CR.
Secondly, people come and go and rarely do all the people we expect to come, come. For whatever reasons people wind up not coming even though they want to or plan to. A vort is not a wedding and no one plans to stay for very long. If you chosson’s family and friends live 2 hours away don’t expect to many to show up and even if they do, they might come, leave for a while and come back. Since it is not a sit down dinner, and it is spread out over many hours the place will be big enough. You have no clue as to when people will show up, so don’t worry so much about it. It is what it is and it will be fine. It falls on your parents shoulders if it is crowded or if their is a problem no yours. YOUR job is to just relax, enjoy and have a great time.