I attempted Vegetarian touring in the late 80's and early 90's. Relatively easy on the west coast. Also fairly easy east coast New Jersey to Maine. Middle of the country I found nearly impossible to comply (except Boulder, CO!). Nowadays, with the prevalence of Subways and Smoothie shops, power bars and energy drinks found in some very small towns, I think I could even do it stove free. I like the suggestions given by others above. I might add that a head of cabbage will last weeks in a pannier bottom wrapped in a couple of bags if the temps are reasonable. I also cook on a mini Trangia - eat from the pot.

OK, the biggest problem I had with staying vegetarian (not vegan) was three or four nights a week, camping neighbors in RVs would deliver meals to me to be nice. Almost every time the meal had lots of meat and dairy. Fried chicken, BBQ Ribs, even steak and seafood, potato salad, mac-n-cheese, etc. Since my trips tend to last six or seven months, it makes sense to take advantage of free food. If someone hands free, hot, delicious food to me, I eat it and show gratitude. That's my rule.