It is safe to prepare your lasagna a few days before and refrigerate or freeze and then bake it when you are ready to serve.  If it is a large quantity if would be a good idea to cool the hot part like the meat first before making the lasagna, is it will cool faster in the refrigerator.  For small quantity it is not a problem if the baking dish is no deeper than 3 inches.  

If it is going to be longer than a few days you can also freeze the uncooked lasagna.  

When you bake it be sure the internal temperature reaches 160 degrees F.

Good luck.  Thanks for using Ask Extension.

Nellie Oehler.