Welcome from Ireland
Welcome to the Quilting Board!

Welcome from Ireland
Welcome from Michigan.
Hello from Western Maryland !!
Maybe you could find some flannel sheets and other blankets at second hand stores? Bless you for thinking of the homeless people who are cold. I know some quilt groups have gotten batting (what you are calling the filling) donated from some of the big batting manufactures for making projects like you are making. Hobbs is one of them, I would also try WalMart if you have one close to you...
Hello and welcome from Perth, Western Australia. Fleece can make a good batting, if you've only got bits and pieces you can zigzag them together.
Well done for doing such a wonderful thing...every time we get a cold snap, I always think of how awful it would be to be on the street.