When i was young and living in Mexico we had the big gathering at grammas house - Everyone would gather there for xmas eve and we would do dinner, read the rosary and a whole bunch of mexican xmas stuff! Starting december 12th (Vigrin of Guadalupe's birthday) the families would begin bringing presents to my grandmothers house and at the turn of midnight on 12/24, my sister (oldest grandkid in the family) would start gathering everyone and start handing out presents.
On top of that each family would keep one or two presents at home to give to their kids just as a formality - Everyone knew the big presents were coming to gramma's house!
My grandmother passed away almost 7 years ago and since then the family has kind of broken up into smaller groups... for a while while i was married the place to celebrate was my house! Of course thins have changed over the last year and the family has gotten a bit smaller but the good times are still there, just with a more close-knit family than before!