Vicki,
As a single mother I don't have this problem (yet, I hope to perhaps one day
! ) I will tell you that when my own parents were faced with this issue they simply put their foot down and told the rest of the pushy family members that they would not travel with small children on Christmas...come to them or forget it. (It worked and by the time my brother and I were not small there were younger cousins and thus began a round robin of taking turns meeting at the homes that had children) You do have a right to do what is best for you and your immediate family... Good luck!