We face this often with our little Bella. She loves to be around people, but I think it gets stressful after a few minutes trying to decide who she should give her attention to and trying to dodge feet, etc. I think she actually is relieved if she doesn't have to be part of a larger gathering. We have found that putting her in her expen in the bedroom with the door closed and the TV on has eliminated her barking. If she can't hear specific voices, ours, she seems to calm down. The TV masks the voices in the other parts of the house. We put food, toys, her bed, and her travel bag (her favorite safe place) in the expen with her. We let her come out when most of the people have left and it is down to the last few people. We just explained to everyone that large crowds were exhausting for her. Although they were disappointed, they understood. Everyone was very supportive. We also can peek on her through the window throughout the gathering to make sure she is okay. Each time we've checked she was dozing or watching the TV, we put Animal Planet on.
Hope this helps.
