IMO, there's at least two huge problems with the idea of a peaceful division of the country into red (MAGA!) and blue nations. The first is that, geographically speaking, the split is not so much regional but more rural/urban, which would make it very difficult in many states to effect a peaceful division. Just look at NC, which is divided almost 50/50. How would you create any kind of geographic division in this state that makes sense and would be workable and practical? And if you try to divide the country regionally and say "well, you conservatives living in blue nation are just going to have to move, and liberals living in MAGA Nation are going to have to move" that's not going to work - good luck getting massive numbers of people (especially rural conservatives) to move quickly to another section of the country. They're more likely to just stay and fight or try to take over the new liberal nation.
But the second and even larger problem - as you alluded to - is the mindset of American conservatives. Most of them would probably rather cut off their right arm than allow hated LibDem elites to form their own country beyond their control and domination. IMO, a huge part of their psychological makeup is having an enemy to fight and rally around, and I just don't see them ever peacefully living with the liberal blue nation that would result from such a split. There would be constant comparisons, constant resentment, constant fear, constant outrage, and attempts to undermine or just take over the liberal nation. And that would especially be true if the liberal nation did better economically and in other ways than MAGA Nation (which is likely to happen). Any problems in MAGA Nation would always be blamed on the evil liberal nation next door that's always undermining their economy and making them miserable. It's what they do, and I don't think a separation would ever be peaceful or tolerated by conservatives for long.