On wide open highways i think speed limitations should be similar to that of the autobahn where it is instructed to drive "Within the capabilities of your car and your own driving experience/abilities." (while obviously paying attention to conditions), because truthfully, I've driven to Florida before on some of the stretches of highway with cruise control set to 100mph and went for hours without having to do anything...
85mph is certainly a step in the right direction in my opinion. 55mph is hilariously slow these days on interstates, 65mph is approaching such...we have areas that are 70, but honestly, when you're wide open in the middle of no where, that feels like a snails pace. That and 85 limits make 100mph out of the range of getting points on your license (at least here in GA, lol).