People on this board really overestimate how much the electoral college benefits Republicans. The fact that in 2000 and 2016 a Republican won while losing the popular vote was simply a coincidence of both the election being really close and Republicans having an EC edge. From 2004-2012, Democrats had an EC edge.
Republicans will never accept any sort of power-sharing agreement under any circumstance. They know that the Electoral College is all that matters and how they largely benefit from it. Notice how irrelevant Trump's seven million vote loss from 2020 is to the "stolen election" discourse. They will never consider abolishing it until they are the ones are the wrong side of an electoral college-popular vote split.
what if the EU/G7 countries side with the NY/CA type states if they threaten secession?
Those nations literally have zero power over the USA, lol. The country isn’t going to be bullied into listening to countries who we had to save their asses in both WW1, WW2, and the Cold War.