The "three forks to rome" section on the owyhee is typically referred to as the "middle owyhee". with stuff upstream of that as the "upper owyhee"
You can do the Three forks to Rome stretch at flows much much lower than 2000 cfs, though higher is better for running Widowmaker if you choose to run it instead of portage. Not sure slamkal how you recommend "down to 2K".
Also, unless you put in upstream and float down to the actuual 3 forks launh site, accessing the hot springs creek (Warm Springs Canyon) is a difficult task that involves taking a significanlty worse road from the actual launch area and driving upstream 2.9 miles where you have to use a boat to get accross the river at higher flows. You could swim it at higher flows I suppose if you were of a mind.