Sorry but Christmas is for children. I personally would say older son and grandchildren for Christmas.
I wish I had had more Christmas days with my grandparents. The grandchildren grow up so quickly.
Could your sister and niece and younger son not come to your house?
But decision is yours. I picked up reading between the lines you want to go to your sisters.
Whichever choice have a fantastic Christmas with lots of memories. Xx
Army horses loose on London streets