So, I made a small one of these as an experiment. It was too small. I could fit my pear and sprouts in it, but not much else. Ergo, I made a bigger one.
Though I have not taken it to the Farmer’s Market yet, I think it is big enough – it fits my summer jacket, a pair of pants, and my thick sweatshirt/fleece coat. Yep, big enough.
Pattern found here – the Mad Market Bag. I, being me, didn’t follow the pattern exactly, but it turned out rather well.