I was just browsing the DAILY all-time low temperature records and it looks like we are very likely to break thousands of Low temp records over the next week or two.
Looking at major cities like Salt Lake City UT, Denver CO, Casper WY, Detroit MI, Billings MT, Rapid City SD, among many others will all break records, if their forecasted temperatures are reached. As this storm system moves eastward it is likely to continue to break records across the US. And it won't even be close to the old records. Most will see the records broken by 5 - 8 deg F.
For the 23 of Dec:
Casper, Wy record -27. Forecast is -33
Billings, MT record -20. Forecast -36
Salt Lake City, Ut record -11. Forecast -22
Rapid City, SD record -28, Forecast -36
I could go on, but you get the point. This is going to be a very cold and brutal winter.
The source was Historical records and the NWS forecasting office. I had to compile the data into a list.