I set my up like a village on top of my dining room buffet. I have a small mirror for an ice pond in the middle.
I too lost my mom about 5 years ago a couple days after Christmas. Each year brings memories of how she so enjoyed the holidays & I like to think anything I do to celebrate is a tribute to her.
Let your grandson choose his favorite ones & have him set them up with you. Sounds like he's reaching out to his grammie to start a special tradition.