How many people are you serving? You said that there were 4 of you, but this is a pot-luck?
I was going to mention pigs in a blanket (cocktail smokey links rolled up in crescent rolls) but then noticed you don't have an oven. These store well in the fridge for several days and are good cold.
Kids want ucrustables, why not make your own PB&Js? Or just put out the ingredients so the kids can make their own . . . I know, I know, it just isn't the saaaame!
A hardy pasta salad . . . grill up some Italian sausage, let chill then cube it, add to your favorite pasta salad (I like the sausage with bow tie pasta, red onion, red & yellow peppers, chopped fresh brocolli. Dress with your favorite Italian dressing.)
Or simply grill up the Italian sausages (or polish or just plain hot dogs), cut them in 1/2 and serve with the 1/2-sized buns with condiments on the side. Or even with the sausages of your choice, you can slice them in 1-inch slices and serve with toothpicks . . . it all depends on your food service set-up.