I've settled on 75F as a working temp because that's the coldest I get out of my taps in the summer, and it's not hard to maintain with my Jobo in the winter. I don't like dealing with hauling ice up and down the stairs from the kitchen to the darkroom and then playing around with adding ice, checking the temp, adding hot water when I've over-cooled it, then adding more ice to bring it back down again. That said, 85 is pretty darned hot out of the tap. I'd third/fourth/fifth(?) the recommendation of mixing up a large volume of water that you pre-temper and then use it to dilute your chems and process your film. The plastic bottle full of ice is a good idea for managing a big bucket or a bathtub full of water.