On a tour, I always recommend riding easy days for the first week or so and then building the daily mileage after settled in to the grind. Not sure if that works for you or not, but it does help avoid overdoing and getting injured an/or discouraged. It also avoids needing to take days off recovering. I much prefer to ride every day or at least almost every day.
Sounds good. My plans are loose. I have goals that will be adjusted as new information (pain) comes in.
I don't know your route, but only a few exceptions on any given route I have done it is pretty hard to avoid going past a walmart every hundred miles or so and impossible to avoid dollar stores. It may depend on what you consider a fortune, but I have managed to eat pretty cheaply even when eating at least one restaurant meal per day. Both diners and Subway usually wont dent your budget too bad. You will undoubtedly have lots of chances to buy real food at a grocery or walmart.
I dont shop at WM and I am not going to leave my fully loaded bike, locked, in front of a large store, even if the route allows me access to one. I dont (when it can be avoided) eat processed food, preservatives, junk etc. My plan may sound weird and convoluted to some, but it is a way to keep some kind of organic source of energy with me. I will of course eat other foods, but I do not want to eat crap out of desperation.
Just a suggestion, but...
I don't know your age or fitness level,
47, F, ride about 80 miles a week, constraints due mostly to work+school. I'd ride all dang day if I didn't have work or homework to do when i got back. I am taking two months off for this

but I know that I personally didn't mind didn't mind doing quite a few 100+ mile days on my last coast to coast road tour. That said it was nice to take some easy days and I wound up only averaging 80 miles per day. I was 61 at the time, not much of an athlete, and didn't train for the trip beyond just trying to remain at a good overall fitness level. Also, an injury slowed me down for some of the trip. Only you can say what will work for you, but much more mileage than that would have been a lot less fun to me.
I will play it as it comes :-D
I'd suggest that you consider taking time to talk to the locals and hang out. See the sights a bit. It doesn't sound like you will be competitive at the pace you are contemplating unless you are at a pretty advanced age and there are age brackets, so treating it more like a tour and less like a race may be nice.
I am competing with me and one other person whom I hope to beat, as yet undetermined. My goal is to a) finish b) not last. What is the point of entering a race if one does not do better than their best? It is always easier for me to assume I can do less than I think I can, if that makes any sense. I am just going for it, is all. As far as stopping, I am trading in my vintage flip phone for a smart phone because it has an app where I can locate an AA meeting wherever I am. To me that would be awesome. AA people are the most. I have been in for 27 years, with four years in between out doing research

Plus I have a woman's AA coin she gave me to take with me, as she cannot travel right now, she would like her coin to see the sights. I plan to photograph it at various spots along the way and email her, like that garden gnome in [In Bruges?]. So, the race does have a spiritual bent to it.