I have tried many things to get the best efficiency possible. REGEN does not seem to have a huge impact on range. I found that i get the maximum range if I vary my REGEN setting. I tried the same trip back to back to back around town to see the difference in REGEN settings. Of course, traffic is NOT identical every time I go, so that may have made a difference too. Just to note, I had the AC off and the drivers window down to eliminate the AC as a factor as you will use more energy if you sit at a light with the AC on or with the AC off.
1) I did the 8 mile trip with REGEN set to 3 in ECO mode. My average mi/kwh ended up 5.6 mi/kwh
2) I did the 8 mile trip with REGEN set to 0 in ECO mode. My average mi/kwh ended up 5.5 mi/kwh
3) I did the 8 mile trip with REGEN setting varying between 0 and 4 (hold down paddle to stop). I would leave the REGEN set to 0 when I was not planning on stopping and if there was a red light or heavier traffic, I would increase REGEN depending on how fast I needed to slow down and would bring the car to a stop by holding the REGEN paddle. I ended up getting 5.7 mi/kwh on that trip.
Based on my experience, the difference really was minimal and it's just too much hassle to vary regen manually, so I decided to just leave the car at LEVEL 3 regeneration..
On longer road trips, I usually set the Cruise Control to the speed limit. On the trip from Florida to Maryland, your speed limit will be between 65 and 70 for almost your entire way. Going above 70 mph OR driving uphill or heavy head wind will reduce range significantly. Wind can make a huge difference.. I once drove from Lakeland (Central Florida) to Fort Lauderdale (South Florida) and got an average of 4.5 mi/kwh going 65 mph most of the trip with tail wind. On the way back, I averaged about 3.7 mi/kwh at the same speed. I actually had to slow down to 60 mph to make it home without risking to get close to running out of juice. There was no Level 3 charger on my route (Highway 27). Now, there is a Level 3 charger at Sebring which is 2/3 of the way from Fort Lauderdale..
Also, keep AC on auto and temperature at 73 degrees or above.. The colder you set the AC, the more power it will consume.