Ah, here it is:

https://www.pbs.org/wgbh/nova/video/alaskan-dinosaurs/

The species they highlighted all seemed to be close relatives of some of the familiar dinosaurs…raptors, horned dinosaurs, T-Rex cousins etc. They didn’t seem to feature any cold-weather adaptations in the fossils.

One specimen they used as evidence was a small raptor’s fossil which seems to have died in its den while “hibernating”, but it was only one isolated example.

All in all, I was disappointed by the quality of science for a “Nova”. But the field scientists involved in the study all seem to have accepted the conclusions I’m skeptical about.

Thanks for the research. I appreciate it.

And I am surprised NOVA did not mention them.

First, the planet was a lot warmer then, there were no ice caps, sea level was a lot higher, the center of North America was flooded from north to south with a shallow seaway.

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

Second, recent paleomagnetic studies suggest that Alaska was much further south, anywhere between 32 and 55 degrees north.

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/29/10/947/191900/Late-Cretaceous-paleogeography-of-Wrangellia

It rather difficult to tease some of these things out of the paleomagnetic data, the difference between magnetic poles and the tilt of the earth itself. Both are dynamic over geologic time.

https://www.sciencealert.com/there-s-evidence-that-earth-tipped-on-its-side-84-million-years-ago

Did the show include a discussion of paleobotany in that area?