I am going to make Ina Garten's pear clafouti with some merely decorative pears my sister has in her house. Can I freeze it? I'm baking too much.

Just be sure those "merely decorative" pears aren't wax or plastic!

A clafoutis is all about the fruit you use, since the batter itself is very simple. So "merely decorative" pears are bound to produce a bland result. Why not try poaching the pears in wine, or a spiced simple syrup, and see if you can perk them up a bit. Once poached, they'll keep for quite a while in the fridge.