Leftover phyllo sheets can be wrapped tightly and refrozen.
How to Prepare with 18x14-inch Phyllo Sheets
Use a total of 9 phyllo sheets, spreading 1/3 of the filling on each stack of 3 sheets and rolling. (You will have 3 logs.) Freeze, then bake as directed. Cut each log into 10 slices to serve.
Omit butter. Spray phyllo sheets with cooking spray instead of brushing with the melted butter.