It requires a combination of good weather conditions and economic driving to drop temp bars while driving at highway speeds.
Generally, you need to be above 4 miles/kWh in efficiency, and have a temp differential between pack and ambient of over 40-50F. If it's 55F outside, you can cool your pack from 120F to ~100F during a 90%-20% drive. That might drop 1 bar on your dash.
I am doing another Kansas run soon, with fingers crossed on optimized driving with 3 DC stops, so will see what I can manage.