Is this a make-ahead recipe?

Could not have responded better than what Lori has said!

The recipe doesn't say it is, but I don't see anything that would prevent it. The formulation is pretty similar to others of this sort, which all do fine made up the evening before and stored in the fridge until shortly before baking. Just make sure your bread is good and dry. If the bread isn't fairly dry, you can end up with a mushy casserole, since you want it to sit overnight to soak up the custard.