Step 1: Make friends with a teacher.
Step 2: Ask aforementioned teacher friend if he/she has any canvas tote bags from "professional development opportunities."
I've been a teacher for three years and already have four canvas tote bags that I didn't have before starting (already had my grocery bags). If you can find a teacher who's been at it for a while, and is also a bit of a pack rat, you may just hit the jackpot. Or you may not get anything... a lot of teachers have so many that they refuse new ones.
FWIW, if mine weren't up in Alaska right now, I'd send you a few, just to be rid of them.