Yes, this dish freezes well. Before you melt the cheeses in the oven, place the prepped and cooled chicken spaghetti into an airtight container (or disposable pan) and freeze for up to 3 months. If you have a freezer to oven safe casserole dish there's no need to thaw it before cooking. If you do not, you'll want to allow the container to come to room temp before baking. Bake at 350F until hot and bubbly.