It's funny you mention that, because I've always found it interesting how both the 2014-15 and 2015-16 Niños had New Years-ish Arctic air. Fascinating that it's a general feature of Niño climo... Given the subtly changing wavenumbers as winter waxes into its zenith then wanes into spring, it makes sense that such a broad and distinct agitator of the Pacific jet like the ENSO cycle would provide certain features with an amount of regularity on the seasonal timescale, within windows of ~1-4 weeks.
A similar feature we've talked about more often on the forums is the warm November - La Niña correlation, with recent (climatologically regular) Niñas in 2008-9, 2016-17, and 2021-22 crashing into December cold out of a milder Fall regime, with even some 70s in early Nov. 1949-1950 is of course the ultimate example of this. I'm curious if you've seen any other correlations?
Aside from that, if we do decide to go down the path of an 1877-78 redux, then considering that event set high water marks still standing almost a century and a half later, our planet may be in for a world of hurt these next 2-3 years. A similar departure from today's average would probably cause some eerily rapid, profound climate change.
The Atlantic is expected to be dead this year with a more active Pacific. My hope is that the west Pacific is active and we get more recurving typhoons it'll help break up the warm water over there. I recall that happening in 2014, but it could help get the PDO more positive.