The overall pattern looks favorable leading up to late December for a potential Sudden Stratospheric Warming Event in the form of a wave 1/displacement event with troughing dominating the Bering Strait & Eastern Siberia and a huge high over Scandinavia, both of which are projected onto the standing planetary wave pattern and will increase wave forcing onto the polar vortex, decelerating the polar night jet, and leading to considerable warming in the polar stratosphere.
The question becomes how significant is this warming, does it actually perturb the tropospheric vortex enough to give us a prolonged period of high-latitude blocking in January & even February, and how will tropical forcing (the MJO esp) evolve in tandem w/ this potential SSWE?
The answers to all these questions are still in the air atm, the MJO's amplitude may increase in a few weeks time though given the polar stratospheric warming that leads to acceleration of the Brewer-Dobson Circulation, ultimately affecting the shear & static stability of the tropical tropopause (in this case, cooling it and thus being more conducive to near-equatorial convection), and typically it takes a few weeks for the tropospheric vortex to significantly respond to a sudden stratospheric warming event like this unless the warming is initiated in the troposphere first, thus I wouldn't anticipate this to really have much of an effect on our pattern until early-mid January.
Until then, the tropospheric vortex will leave North America and migrate towards Siberia, temporarily exhausting the North American continent of cold air. However, as the vortex digs towards Siberia, it will induce downstream ridging in the NE Pacific and Alaska, (-EPO), which will then reload the continent with cold air and create a pattern we've come to all know & love the last several years in the southern US, giving us a favorable look for wintry weather in the southern US yet again as early as the last week of December, with the SSWE potentially influencing our chances in January & beyond perhaps.