I also bring a little portable propane grill and tend to do something easy like brats or burgers for lunch.
For breakfast, I like to make fixings for breakfast burritos ahead of time and bring it up in the crockpot. I usually am feeding 5-7 guys and I’ve found that about 36 ounces of ground italian sausage and 2 dozen eggs to be a good ratio and will feed the group for 2 breakfasts. Obviously you can scale down the quantities to your needs but that is a good ratio. I also like to do a mixture of sweet and hot italian sausage. Brown the ground sausage in a pan, drain the greese, add to crockpot and then cook the scrambled eggs and add to the crockpot. When I turn the crockpot on in the morning to heat up, I like to add about 1-2 cups of cheddar cheese. Pretty minimal effort meal.
For dinners, I have found that making sloppy joes ahead of time in a crockpot is a tasty and easy meal.