Why does the vast majority of the opposed side think that Nukes would fly on day 1 leading to a dumb and boring game?
In the early years no side could declare war on the other since World Tension would be too low. By the time two super powers could throw down MAD would be part of the game and as such you'd loose. Fine, most would try it once, but after a full up nuclear exchange when you go from world super power to blasted wasteland and the game mechanics force you into a peace with everyone and an automatic loss for ending your country then it's not a big deal, nor "un-fun".
The best part of a cold war mod is how to steer your country through MAD and control the world's resources without losing. You'd be fighting proxy wars, getting involved in civil wars, shaping your industry and technology, installing puppet governments etc.
Even the industrial aspect is easy with HOI4 if you add a dissent mechanism. As the game progresses your populous demands a certain standard of living, such that you need to keep up civilian factory output and civilian research tech (or NF).
The biggest challenge is finding multiple exits from WWII based on war weariness like the Korean war. Then you could have some fun.