According to some, the earth may have 10 billion people living on it by the end of this century. There is genuine concern about space and resources.
Imagine, then, 100 billion people being resurrected to live on Earth. Some JWs will argue that not everyone will be resurrected to Earth, including 144,000. Imagine 50 billion then, assuming that half of the people who ever lived did something so horrific that they aren't deemed worthy to be resurrected.
JWs who are lurking and reading this: Where are they going to live? It's impossible for this to happen even if there are no more cemeteries because there are no more dead people (When I was a kid, and I asked where will people live, I was told to think about all the acres of land we will have with no more cemeteries, zoos or jails).
I have been away from meetings for maybe 10 years. When I was active, JWs would argue that there will be new scrolls and that the universe is so big and maybe there will be other places to live. Factually, there have been earth-like planets discovered. However, the hope of living on one of those planets based on JW teachings is purely speculation, a wish. The bible says nothing about it. It only talks about how the Earth will never be destroyed.
So, think with an open mind: Based on what you know and what you have studied in the bible, where would all of those resurrected people go?
And don't forget about needing space for all of the animals.
Sources:
http://www.prb.org/Publications/Articles/2002/HowManyPeopleHaveEverLivedonEarth.aspx
http://www.bbc.com/news/magazine-16870579