If the baby starts crying late at night or early in the morning turn the fan inside the camper on high and step outside. You will be surprised how much the noise is dulled by the fan. I have also taken my boys out for early morning drives, most recently around the Park Loop Road in Acadia. I have actually come to enjoy such pre dawn rides.
Overall, when travelling with newborns here is the best advice I can give: know where the nearest hospital is, stick to your normal routines, and bring extra coffee!