If you sous vide at home, it is perfect for camping. Just sear the chicken or steak over the fire. Also easy, pick up great chicken sausage and buns, serve with baked beans, and raw veg. If camping in fall, make chili and warm over fire.
What kind of steak? Over-marinating can turn a steak into mush. Two or three days is way too long. Just put your refrigerated steak in your cooler and if you must marinate, do it the night before you cook.
Skip the Tupperware (takes up to much space in the cooler), just go with zip lock bags in various sizes. As far as leftovers, slice it up before putting in the zip lock, will make steak sandwiches or steak salad for lunch the next day that much easier.
Agree that freezing for night 2 is not so necessary.
Also -- if you will be handling raw meat at campsite with no running water, make sure that you set up a handwashing station before you start dinner prep.
What will you be cooking on? If you are planning to cook directly on a fire grate, bring aluminum foil, just in case you don't want to put the meat directly on the grate.
If you think you will have leftovers, don't forget some tupperware containers.
I wouldn’t bother freezing it. Unless you have a really crappy cooler, it’s going to stay mostly frozen in the cooler for night 2. Then you’ll have to either cook a partially frozen steak or set it out to defrost in hot temps (assuming you’re camping local), and that’s gross. Just buy and marinate the day before you leave.
Rookie camper here and I'm in charge of dinner for night 2 of a camping trip.
I want to do as much prep here as possible, so was thinking of marinating a steak and then freezing it, and bringing it frozen, assuming it will thaw a bit in the cooler.