We travel a lot. DH's family lives five hours away and we travel there usually once every eight weeks or so. They own a timeshare with tons of points so we travel often with them to those places, as well. When we go, there's myself, DH, our daughter who is 23 months, and usually my two nephews, ages 8 and 12. For the road, I pack a small cooler with water bottles and Crystal Light packets of lemonade, and a variation of string cheese, small packages of crackers, Ziploc bags of goldfish (I actually get the Whales brand at Dollar General for $1/box), carrot, celery, broccoli, and bell pepper sticks, bananas, and grapes.
We like to try and reserve a hotel with a kitchenette (usually they at least come with a small fridge, coffee pot and microwave anyway) so I can have a small stove to cook on. If not, I bring my crock-pot. Once I get there I do a small shop to pick up ONLY the ingredients I need for the meals I need. I get breakfast foods (usually bagels with cream cheese, pre-made muffins, cereal, milk, OJ) and we always, always eat breakfast in the room. Depending on what we're doing that day, I might plan for sandwiches and veggie sticks or even leftovers for lunch and either take them with us or eat them there at the room. If I don't have a stove, supper is usually in the crockpot -- I have a great recipe for crockpot bbq beef (sooo yummy!) that you can eat with hamburger buns or even regular sandwich bread. You can even take two crockpots and make a veggie in the crockpot, or potatoes or something.
Do you have a travel grill, or even a George Foreman? That might come in handy, too.
I find we save literally hundreds of dollars by eating mostly in the room. We bought a travel sized grill that folds up for $30 from Home Depot and it has paid for itself over and over again. Take it out on the deck (if you have one), throw some veggies in aluminum foil and whatever meat you like and it's delicious.