I imagine if you were on one of those planets it would also become very cold, very quickly.
Great story though! I really like reading these sort of articles, it’s nice to get a break from politics once in a while :)
I doubt that you would notice.
The torsional tidal forces exerted on the planet when it was torn away from its sun would be such that the mantel of the planet would be cracked like someone roll in a hard boiled egg between there palms. There would be little left on the surface of the planet uncrushed. The gravitational shear may tear the atmosphere from the planet.
If you want to make the story line plausible, you could posit the existence of high geothermal heat at the planet’s core making it somewhat warm but still, of course, dark on the surface.