The Flu, while nice lore addition, really does freeze you in place for years. Hell when it hit I looked up how long it lasted in the actual lore (42 years) and was terrified I might be stuck with it for nearly half a century! Luckily it only went on for around a decade or so, though I still had to evacuate my retinues because even the damn capital had such a crazy attrition rate (Sent them on boats into the ocean to not have to disband them or pay a fortune to rebuild them continously for years). By the time the flu was done several of my family branches were nearly killed (Which would have sucked since I was planning to set each of those branches up with a High-Kingship at some point in the future), and I think the only reason my close family members didn't die was cause I used boats to save them like my retinues. (Not complaning that it made the game harder just saying what happened). Also hilariously the Argonian lands were immune to the Flu but Atmora wasn't (Atmora being filled with only undead makes me wonder how the hell the flu spread up there), also it noticably lost steam by the time it Reached the Imperial city, and by the time it finally infected Alinor it only stayed around for a few months (Compared to the 3 years in the Imperial city and 10 or so years the last remnants of the flu remained active for in Akivir) Over all the flu was devastating (I inherited countless duchies that I had just landed so no family to inherit) and crippling to my warplans (Though luckily the flu was slow enough in crossing from Akivir to Tamriel that I could conquer a few lands here and there before it showed up), but a nice little addition to lore that only through slight cheating (boats) keeps it from being absolutely frustrating instead of a novel addition.