It strikes me the entire season should have been about the war with the Ice King. Another season could have been devoted to the war with the Lannisters.
shareThey should have fleshed the NK side of it out. Given us some more backstory on him and his intentions perhaps. Lots of possibilities there. I don't think one season had to be devoted just to him, but at least have more episodes to better build up his showdown with our protagonists, and give the "Long Night" the duration that it deserved, and even integrate it into the goings on at King's Landing.
Eight seasons might have been enough had they been 10 to 12 full episodes.