Easy for the doc to say - he/she's not being woken up by a crying baby.
Personally, for the sanity of everyone in the house, I let night-time nursing go on long after they stopped nursing in the day. I was desperate for sleep, and if I could roll over and make the baby stop crying immediately, and fall right back asleep myself (bed-sharing) I was gonna do it. It was like magic.
Eventually, they do nurse for shorter times, and wake up less frequently, especially as your supply goes down (and if you're only nursing at night, your supply WILL definitely drop.) Although comfort nursing (even with no milk) is a excellent soother, too.
When I got pregnant with my 2nd, the milk supply REALLY started drying up, a little TOO fast, so I gave my nighttime nurser a big cup of honey milk or (not too sweet) chocolate milk just before bed to keep his tummy full longer. Sometimes he'd still wake up and he would need a little help going back to sleep, sometimes I just had to touch his head, or even if I snuggled close so he could feel my breath on his head. Other times he would comfort nurse for a few minutes, but there was so little milk there, he didn't get much if any. And... gradually things tapered off on their own and we never had any tears.