Just a tip. Those boxes are awkward to carry around and sometimes wind up leaking. Since one of us usually caries a backpack, we pack a couple of the disposable food containers in it for just such a occasion. We transfer the contents of the To-Go box discretly into the disposable container and happily go on our way knowing that the one with the backpack won't spend the rest of the time with something dripping down his or her back.
The containers are light weight and who cares if we wind up throwing them away instead of taking them back home. But they do wind up being helpful for stowing leakables in for packing into suitcases.