Canada, NZ, or Australia?

Hi all, I'm a federal government scientist looking down the barrel of likely firing in the next couple of months. We are trying to proactively look into options to get out, and like many English speakers, our leading options are Canada, Australia, and NZ. Any advice or experience from those of you who have already left the US would be very helpful. Here are some more details:

Me: 40M, PhD in Astrophysics, involved in Mars rover missions since 2006. Skills in Python programming, machine learning, GIS, spectroscopy. Sort of an academic jack of all trades.

Wife: 39F, MS in High School Physics teaching. Stay at home mom since 2019.

Two kids: 8M, 5M

We are all US-born citizens. We have some basic Spanish, and I have even more basic French, but prefer to go somewhere English speaking if possible.

Potential interesting wrinkle: If I lose my job, it is possible that my funding as part of the rover missions could be transferred to an institute that allows people to work remotely from abroad. I am unclear on whether the countries we're interested in would allow that and how it would affect progress toward PR.

Any and all advice welcome!