Here are a couple of images showing estimates of the minimum surface temperature observed by these satellites on January 18 over the Fairbanks area and points eastward into the hills; this is the day that temperatures bottomed out during the cold snap. I've interpolated the data to a 750m grid in both cases for consistency (click to enlarge the images). The similarities are striking, but greater spatial detail is evident in the S-NPP (lower) image, as expected.
It's gratifying to see that both maps show the cold conditions on the Salcha River in the bottom right; the Salcha River RAWS (SLRA2) reported -59°F, and the satellite data support this very cold reading. On the other hand, the -65°F reported by the Upper Chena River HADS site (UCHA2) is not supported and was almost certainly in error.
Below is a comparison of the minimum temperatures (in °F) reported at each of the sites marked on the maps. The agreement is, in my view, quite impressive, with only the Stuart Creek RAWS seeing a substantial difference if we exclude the Upper Chena HADS site. At both Stuart Creek and at the Salcha RAWS, the estimates are better for the S-NPP, which probably reflects the superior resolution of the S-NPP instrument.