Importantly, how are we doing in terms of coverage? Are we seeing the sky enough and clearly enough to have a few years worth of warning before we get dinosaur-ed?

I figured the experts here would care to express an opinion.

Good question! From working within the field, there are new missions like NEO (Near Earth Object) Surveyor whose mission is to identify objects that could possibly be hazardous. There have also been missions previously done to study the required response to alter trajectories of objects such as the DART mission. We will also have a much greater picture of asteroids and comets in the inner Solar System in the future as the Vera C. Rubin Observatory continues its Legacy Survey of Space and Time (LSST) over the next decade. People are definitely thinking about these problems!

Links:

https://science.nasa.gov/mission/neo-surveyor/

https://www.youtube.com/watch?v=N-OvnVdZP_8

https://rubinobservatory.org/news/11000-new-asteroids

https://en.wikipedia.org/wiki/List_of_predicted_asteroid_imp...