I definitely like the votive candle idea. Linking the remembrance of the loved one-then linking it to the true Light (message of Christmas). We tend to get wrapped up in all the busy-ness of the season and forget what it is really all about.
I envision someone sitting and starting to tearfully unwrap all the Christmas ornaments, and being unable to deal with the Santa's, elves and shiny stuff for the tree. Then opening the box with the Nativity crèche and a single candle, while reflecting on the meaning of Christmas and talking about how (grandpa) loved the story of the birth of Christ and all it's true meaning, as they set up the crèche on a small table.
As they talk through their emotions, they link the remembrance of their loved one to the candle and to the meaning of Christmas. They light the candle saying something like..."this is all I really need this year. Happy birthday, Jesus. Merry Christmas grandpa."
Then close one of the other boxes and walk off stage
Then have people come and light a votive candle and leave taking the (takeaway gift).
For the remaining Sundays until Christmas, simply have a single lit votive candle on the alter or stage, along with whatever else you are decorating with. Those people will know.