I've also not had a problem taking leftovers home. Some use proper containers, some foil, but I've always been okay to bring it home.
What's hard is for work, we go to an American BBQ place pretty frequently and people love to order the Challenge which is a £40 platter of various meats. They NEVER eat it all and I can't take it home for my husband as all the sauces contain gluten. Oh well! Boy, would he be a happy bunny if I did.