Sorry, I'm coming up with a photo-album/scrapbook type thing. But, I would just cut out the part of the sentiment and added notes and creatively display that rather than having to open a card.
Also, regarding X-mas cards. One thing I started last year (as I have kept these cards for years and, like you, will someday do something with them!) I started a "Christmas Card photo album". Many people are sending photos or photo cards and so, last year, I compiled them on a page (or two) per family. One of my cousins have been sending me photo cards for about 15 years and I found about 9 years worth. It was so fun to see how their kids and the families have grown. Generally I have 3 or 4 years of Christmas card pictures, per family. It turned out so cool. Didn't use any scrapbook materials - just used artwork from a few other Christmas cards to make it more festive and fill in the blank spots - until next year, when I can update.
So sorry for your loss. It's nice that you are doing this.