Personally, I think this is dumb thesis, because we can already project seeding our solar system with (virtually) current technology. It may be unecomical to ever move much mass off earth including significant numbers of human beings, but that doesn't preclude seeding planets, asteroids, and dyson swarms around our sun. Trillions of humans can be sustained in just our solar system, and with that base it is an easy stretch to utilize star seeding probes. A seeding probe could conceptually carry little more than information, some dna or the abiltiy to build it, and some nano technology to bootstrap up an infrastructure from energy of a new sun.

It is really very simple once you harness AI and a bootstrapping robotic based system to acquire resources and build habitat. Using machines to acquire resources off the moon, and asteroids and then building space habitats soaking up solar energy is really fairly straightforward from where we currently stand technologically. We don't have the will to do it yet, because with current technology it would be extremely costly, but the costs will drop as AI improves and nanotechogy enables more and more efficient exploitation of all resources.

I came up with the Fermi paradox independently in my youth and only later found out that it had been formalized by a famous scientist. I also through thought experiments came up with the only solution that seemed reasonable. This solution has also been arrived at by others. I favor the "technological singularity" solution. In a nutshell, I believe that all intelligent species are funneled necessarily towards an understanding of the universe that makes it irrelevant are unpalatable to expand into currently known physical universe space.

I believe in emergent intelligence and our sum total is evolving into a mass mind and another level of life (as a cell is to our body we are to this new life form). This emergent intelligence will perceive of new opportunities (other dimensions, virtual reality, energy matrices, etc.) and the direction of evolution will veer away from popularized hard sci fi spaceship expansion into our (currently) known universe. I also think this must happen relatively soon, because we currently are on the verge of the very kind of expansion that would violate the Fermi paradox.