Mishy, Good luck with your family gatherings. They can be so stressful.
Debbi, Caleb uses a weighted vest at school and loves it. It does seem to calm him. We haven't gotten one for him at home yet. He improvises though. He puts Luke's diaper bag backpack on when he gets overstimulated and that weight seems to help. He might be ASD, but he's got some great problem solving skills.
My guys also really benefit from joint compressions. The Ot showed me how to do them. They give the kids some proprioceptive feedback and help center them.
Bless your heart.