My experience is that if you have any type of status and contact the hotel directly ahead of time, they'll try to find a way to accomodate your party without trying to force you into buying an extra room. That said, the hotels can't be expected to knowingly sell you any type of accomodation that violates local fire codes.

As a practical matter, hotels will normally "look the other way" if you try to put five people in a standard-sized room. By you making that decision....and not the hotel....they're not violating a fire code...you are. You're also, in my view, taking on any responsiblity or consequence that may come with breaking local law.

I'm not saying you should or shouldn't "overoccupy" a room. But I'll admit as a father of four, perhaps back in the day, I've "been there/done that"...maybe once or twice.