I agree with V. Change the meat on the meal you ate to high quality steak, and you'd be good to go. Or add avocado or mayo to your chicken...

My favorite go-to cold meal is tuna salad on a big bed of greens. I use tuna packed in oil, homemade mayo, celery and onions in the salad part and then I dump it on a bed of spinach/baby kale and red pepper strips. If I know it'll be a long day, I'll top it with some avocado chunks for extra 'staying power'.

Lettuce wraps with either the above tuna salad, or cold steak and avocado are good, too. Or lunch meats, rolled around stuff is good as well. I like roast beef or turkey with avocado, red pepper strips and and spinach in the roll-up.

I also make kale meatballs (kale, onion, sausage and ground beef and spices) that are good cold and very filling. I carried a bunch of these in zip lock baggies on our kayak trip a few summers go and ate them as snacks. As long as you can have a little soft-sided cooler with and ice pack, you are good to go!