Another vegetarian, I'd always have a backup meal or two, maybe just a jar of peanut butter and a pack of tortillas in the bottom of a pannier, just in case you find yourself needing food. It's not a bad idea even if you don't have dietary restrictions; I've rolled in to town after all the restaurants have closed.

If you have emergency food and aren't afraid to eat it, then the worst that can really happen is a few to many meals of peanut butter. A lot of smaller places can probably make you something vegan if you ask nicely.