When my parents were alive, we went to them for every Pesach (whole yom tov), with eventually five children kinehora. My husband and I schlepped all the Pesach pots and necessities down from their attic and turned the kitchen over for my mom. Then, I helped my mom cook.
We came over a couple of days in advance in order to accomplish this. I never treated this as a vacation and my mom never expressed a feeling of being overwhelmed. We took care of our kids, also, and kept them entertained so my parents could nap after lunch. There is no excuse for any young couple to treat a yom tov visit as if they are going to a hotel, but I know several such couples, Poster’s well-expressed comments notwithstanding. If this happens it ius up to the grandparents to SPEAK UP!