BJ, I do similar to what you do. When my scrap bin is full, I put on an audiobook and cut, cut, cut until the audiobook is done. Just like you, I have pre-determined sizes that I cut everything into. I finally learned that there was no point in saving this scrap fabric forever when it could be used. There will always be more scrap fabrics. :)
When I housesit for my sister (something I will be starting tomorrow), I take one of the boxes of precuts with me and sew, sew, sew.