Good fall paddling options are usually slim w/o 3+ hours driving. snake below jackson , green river daily, moab daily, split mountain, and "bliss section" of snake, are a sure thing. if your lucky, low water cross mountain trips can be had in the fall. Westy and cataract are great in sept/oct...fall really is the best time to hit those up as the weather is almost always bluebird and not plagued by wind like some of the the spring trips can be. permits seem easier to get in the fall too.
Murtaugh can be run down below 1,000 but, it makes for a long day. Pretty much everything "murtaugh/milner" is "dependent on needs of irrigation" and so nothing is guaranteed. There are variables that can be exploited by those that pay attention. High runoff/good snow-pack typically results in springtime releases but, not always. I remember it going from many thousands of cfs (for a couple of days) down to 10cfs overnight during one spring of a perfectly bountiful water year in the 1990's. I have seen "draw-downs lasting for a few hours to a few days in january/feb that bring the legendary connection wave back to life. I have taken advantage of unscheduled/emergency dam maintainance releases at random times of the year and Murtaugh usually has a "fish" season...meaning that, when surplus water is available, they let a bit more through the canyon when fish are spawning. I have been running murtaugh since 1985...try to pay close attention to the releases and my understanding of why/when they release water still feels like it's in it's infancy. It really does seem like someone turns the tap on/off at a whim. Are there other murtaugh regulars who see it differently?