Absolutely! Listen to Dave. Socialization, as long as you don't overwhelm him, is SO important!!!
Just make sure he doesn't become a "play thing" for the children, or something to be snuggled and squealed over by the adults. Put him in a quiet room, in his crate, and ask people to come and visit with him quietly, a couple at a time. Ask everyone to sit on the floor with him if they are able... Puppies can be wiggly and jump, and that can permanently damage their growing bones. If an elderly relative wants to meet him, you hold him, and let them pat and talk to him.
As far as the other dog is concerned, if it is very quiet, and they are SURE that it gets along well with puppies, you can introduce them, first by letting the dog that lives there sniff him though the crate. If there is ANY chance that the dog will be rough, wild or unfriendly, keep the door closed between them. A bad experience with another dog is worse than not meeting him at all.
Since he's pee pad trained, that part will be easy, but make sure you set an alarm to remind yourself to get him out often enough. It's easy for US to get distracted during a big family gathering too!