I would do exactly that... and have, in fact, done exactly that. I have a little boy that when he first came, there was clearly no nap routine or schedule whatsoever. From talking to mom, it sounds like they do go in and get him, as soon as he squawks a little. I was leaving him for a few minutes, and then going in to get him, because I was so worried he would disturb everyone else. (They are in separate rooms, but directly next door to each other). Then he was absolutely exhausted within an hour or two. And you know how that goes!!
So I began leaving him a little longer. And wouldn't you know it, he will settle and go back down after about 10 min of fussing, sometimes 15. He is still the first one up, so what I usually do is leave him until last to put down after lunch. Every once in a while, he wakes the others, but I leave everyone and it usually quiets down again.
If you are worried that it's a disturbance, I would for sure switch him to the basement. And he will very likely learn, eventually, that at your house it is nap time in no uncertain terms!