My D did both NY and Chicago Unifieds. Parents were, indeed, in the hallways, which got crowded, but I managed to find space to sit either on chairs or even once or twice on the floor. If you go to the ends of the halls, there is sometimes more space.
Speaking of space, something we didn’t know until we arrived at NY unifieds is that they rent out studio space there for warm-ups. I think it was $15 for 15 minutes, but I don’t remember for sure. D did that once.
Wondering if anyone had a situation at Unifieds with illness…like I know you are putting a lot of eggs in one basket and did anyone fall ill and it not work out?
By the time one of my sons got to LA Unifieds (after we’d already been to several on-campus auditions and Chicago Unifieds) he was pretty sick and had no voice left. It was pretty obvious and the auditors could tell. One school asked him to submit his audition cuts on video, he did so on the spot (had them in his phone) and was ultimately rejected. Another school asked him to do the same thing and he was ultimately accepted. So, I guess you never can tell. Here’s the thing: Stay positive. Eat healthy. Wash your hands often. Take your vitamins. Do your best. Don’t dwell on the negative possibilities. Get your cuts on video just in case. And go get 'em. More than likely you’ll be just fine. Aforementioned son and his twin bro are now senior MTs. Unifieds seem like eons ago. 
It seems that submitting video auditions is also an option for some programs if the winter weather goes to h*ll and either the school reps or the student can’t get to the venue.
^ I cannot stress that enough! When I auditioned for Viterbo at NY Unifieds in January 2014, it was the polar vortex and all flights out of the Midwest were grounded. There were no faculty at NY Unifieds, consequently. I ended up auditioning for an alum (and being waitlisted, and being accepted off the waitlist). Viterbo really trusts their alums, so I had a good audition still working in my favour, but the faculty really got to know me through the videos I had uploaded to Acceptd.