Yeah this is what came to me too. It would be a wretched and precarious time…still very dangerous too (maybe we lose some main characters along the way)…but, it could also be a time of statesmen/women and later lionized heroes who brought us back from the brink of total extinction. Including those who butted heads with each other as they did it. A bit 1776, a bit For All Mankind, a bit The Expanse.
Each alien you first introduced would be an opportunity to make a big thing that you did something different with each time. Vulcans, Andorians, Tellarites, Kzinti, Orions, Nausicaans, others…esp those in that scene from Journey to Babel. Also maybe you introduce a species that’s ubiquitous but that goes extinct by ENT.