Man, four clear nights in a row in Tucson is basically a gift from the astronomy gods. I fought that same battle for years and the one thing that saved my sanity was getting my polar alignment dialed in tight every single session, even when I thought it was already close enough. The other trick is to grab your flats and darks right after each night instead of waiting, because the sensor temp matches better and your stack comes out way cleaner. That desert sky down there is no joke though, you can pull detail out of the dust lanes that most of us just dream about.