I don't think he's advocating indefinite growth as much as observing that there are fewer houses than people/families whom want a house. We don't have enough housing to meet the demands of the current population.
Very noble, but ever thought that thinking in terms of billion years is not really productive, and in fact can be counter-productive and destructive?
What with "thousand year" projects turning dictatorial and even "hundred year plans" looking obsolete and becoming laughing stock a few decades after they were devised.
I don't see how one can purport to be the judge on how future generations should live for them, and what the end goal should be millions of years ahead.
Besides, the Sun's death is a really minor issue. It's avoiding the heat death of the universe that will take really good planning...
We're a long way from being able to do so in a population-saving way.
Which planets and moons in our solar system could support human life? Apart from the Earth, the answer is none. We may be able to build small colonies on Mars and/or Europa but the difficulty in building sizeable colonies in/on these places would be huge (cost of transport, cost of base building and maintenance, differences in gravity, decreased sunlight, transforming local resources into forms we can more easily use, etc...), the effort would be much better spent securing the life-support mechanisms of our own planet.
Really? Is it impossible to have a fun and healthy society without a rising population? That sounds like a pyramid scheme.