While this may not be practical for mortals, Jesus would probably open the border and welcome everyone in. Then folks would come to him and say, "you're crazy." "There isn't enough bread to go around." "There's only two loves."
Jesus would then say, "don't worry there's plenty." He would start cutting the loves and everyone would eat. Miraculously, there would be 7 loves left over after the feast.
It's something to think about, but problematic in our practical world. I wouldn't recommend trying it literally, but it's worth a thought. For instance, scientific innovation may not be a worker of miracles, but it's better than nothing. When people say, "there are too many people and too many cars, the traffic's terrible," get folks to ride the bus. When New York City was considered too big because there was no place to put all the horse manure, the streetcar came along.
We can build up, instead of out. Up zone for density. We can keep adapting for a while, but short of something miraculous, birth control, in the countries where the immigrants come from, is needed also.