Im not sure why you are asking about charging to 100% vs 80% for that commute. My commute to my work location is virtually the same (82-83 miles round trip). Whether you do it 1 day a week or 7 days a week really doesnt matter for this, because you should be charging every evening when you return home.
There is no benefit at all to "running it down to charge it back up", so if you are thinking you need to charge to 100% so you can try to charge every other day or something, dont do that, there isnt any reason at all to do that.
Just make sure you have some form of 240v charging at your home location, then, when you return home from your work commute, plug in and have the car set to 80%.