Can this spinach lasagna be made ahead and frozen for one week? I have a large party coming up and need to do ahead

Yes, I think so. Make sure the spinach is really dry. Let the lasagna cool completely and wrap it well before freezing. Defrost it in the refrigerator overnight before the day of the party, and let it come to room temperature before cooking. It still may take more time than baking it fresh. But I can't imagine doing a big project like this on the day of a party.