This does not answer the question as to how much waste you will have but I have a suggestion for using the waste when it comes to tiny pieces... if you have a Humane Society or Pet
Shelter in your town or near by - make pillows out of the left over pieces and donate those pillows for puppies, dogs and cats to lay on - they love pampering too - and most places will lovingly accept any donations like that, that you might have to offer; they are easily washed, and dried and reused once again... Just a thought. My sister-in-law does many quilts, and custom sewing - so she has many scraps! She also reupholsters furniture - so the old seat covers, she washes, regardless of what they look like after they've been washed, and stuffs them with left over fabric and sews them up into a nice pillow and she has taken a pickup load to the shelters and they just give the biggest smiles - their animals will have nice fresh new beds!