16, layout 7, or a Casita
16/17 Spirit Standard both sleep five, and you might squeeze three small kids in the dinette bed to make six. However, both are fairly rare on the used market. Theoretically, the Casita
can be ordered with both side bunks and front bunks, but I have yet to see one built that way. Upper bunks are typically weight-limited, though in Scamp's case there is no official word on what that limit is.
An alternative to a tent for overflow is the tow vehicle. Some fold fairly easily to make a flat place to sleep. It's not clear from your original post what you have in mind- "smaller" can mean different things to different people. Our girls sleep in the back of our Pilot sometimes.
Tent trailers are more trouble to set up and tear down, especially in the rain, but they do provide a lot more space for the weight
. I've always liked the vintage Apache hard-side folding trailers. Thought about trying to snag one of those? They're out there, and they seem to have somewhat of a cult following not unlike vintage eggs.