I got my S85D on June 2, 2015, had the windows tinted on the 3rd and took off on a 3,300 mile trip on the 4th from Austin, TX to Jacksonville, FL, Atlanta, GA, Birmingham, AL, and then Memphis, TN. As previous said, the DeFuniak to Lake City, FL is the longest jump on I-10. I was driving 70 mph when I started from DeFuniak and the Nav system said I would have 6% battery left after I got to Lake City. I am a cyclist and know the benefits of drafting so I drafted 18 wheelers most of the way. The Nav system eventually got up to 13% battery left when I arrived in Lake City.
I used Super Chargers all the way to Jacksonville and dropped down to the St. Augustine SC as a side trip. Charged in Jacksonville on my friends dryer outlet to start my drive to Atlanta. Charged at the SC in Atlanta for my trip to Birmingham. Charged at a free level 2 charger in Birmingham since there are no SCs there. I stopped in New Albany MS at the library and charged up enough to make the trip to Memphis. I arrived with about 20 miles left. There are no SCs in Memphis so I charged using my cousin's 50 amp welder receptacle.
To get back to Austin, I took I-55 South and spent the night in Jackson, MS at the Old Capitol Inn. They have a HPWC there for quests. This was a another long jump of approximately 220 miles so I did more drafting. In the morning, I continued South to Baton Rouge and then West on I-10 and NW on highway 71 back into Austin.
The only range anxiety that I had is when during a tropical storm in Houston made it difficult to see the signs, I saw an HOV lane sign and took that exit. Bad news is that I was on the 290 HOV lane which has concrete barriers on both sides for 15 miles going NW. After I got out of the HOV lane, I headed South and got back to I-10 and arrived at the Columbus TX SC with about 20 miles left in the battery.
It will be great when Tesla installs SCs on I-20 from Dallas heading East. This will allow me to get to Memphis, Birmingham, and Atlanta without having to go South to get on I-10.