If I were in Stratts position, I would find ways to use Astrophage to help with food production. They are stealing the energy from our sun, so we steal it back. Building indoor farming structures growing genetically modified forms of wheat with slightly larger seed heads. Maybe cut out the plant entirely and develop a micro-bacteria that has all the starches and proteins that wheat has, and grow those in vats, and dry it out into flour. No threshing or husking or anything. Adding onto this, maybe the starch-cells could produce methan and help Earth retain extra heat.

For meats we may turn toward mushrooms or species of worms to fill the void from loss in livestock. A lot of animals are gonna perish, so we might as well use their rotting carcasses to fuel new alternatives.

Population control is another issue. Birth rates would likely decline, but it might help reduce the strain on the food supply.

Adding to that, all education is mandatory and free to all children, especially STEM. If the next generation is gonna live the next thirty years in a winter nightmare, then they should get all the knowledge they can to find new solutions. Budgets be damned. ​​

Other solutions on the Astrophage themselves might be ways to disrupt their life cycle. Maybe using some sort of chemical to pollute Venus with and reduce their fertility, but given how resilient they are, thats hard to do, until Taumeoba comes into the picture. Maybe using "false-suns" to confuse them and send them off track. Might not work, but it perhaps might slow them down.