Ugh. I hate this idea. Unless your "party" is less than an hour it's really inconsiderate to not provide the hospitality of seating. What actually encourages mingling is having far more chairs than guests - people will get up and move around to different conversation "pods" because they know that they can always find a chair. Uncomfortable guests tired of standing simply leave.
yea i agree it is better to have more chairs or even better couches with a small table in the middle.
It is very difficult for the guests without any seating in the party. Everybody can't stand for that much time. So, considering chair rentals is best choice.
Let us know what you think.