I'm in TX where the speed limit is 80~85 MPH on my 65 mi. (round trip) commute. I travel almost the entire route at that high speed. My current ride is an SV650 which averages about 40 MPG under these circumstances.
One question - is that a GPS-corrected 80-85 mph? Bike speedometers are notoriously optimistic (I rode a GS500 for a while, it was about 10% high).
Does anyone have experience with a similar situation? What would the expected range be at a continuous 80 MPH?
You lose about 18% of your range increasing speed from 55 to 70 mph. 80 mph would probably lose another 18%, leaving you with 66 miles on the ZF13 and 80 miles on the Power Tank bike.
The Power Tank bike should be able to do your commute, with a little extra left to increase your speed or for headwinds, hills, lunch / errands etc. The ZF13 would need either a slightly slower pace (75 mph would be okay most days) or charging at work.
One other thing to consider is that the pre-2016 bikes will reduce power at low charge, perhaps around 20%. I'm not sure if this is true for the 2016 bikes, which use a tweaked battery cell.
What's the probability that it'd overheat in this situation? It is Texas and it not uncommon to see 100+ F in the summer.
Zero claims 85 mph constant for the pre-2016 SR, 95 mph constant for the 2016.
Zero's range claims and sustained top speeds are likely under ideal conditions: flat, light rider in crouched position, no headwinds, moderate temperatures. With that said, they seem to be accurate under those conditions and sustained 85 mph should use much less power than sustained 95 mph (by about 30%). So I think you are probably okay on the overheating condition, but as others have said it will require warmer days to have real world experience.
Ultimately the best way to find out will be to try the ride yourself. A dealer that is motivated to sell the bikes might let you take one out for a 65 mile test ride so that you can see for yourself how the bike behaves. I would also want to see if the bike reduces power at low SOC.
If you can charge at work you wouldn't need to have the power tank, but if you can't then you would definitely need one.
A commuter screen makes about a 5% difference at 60mph. I don't know if the difference will go up or down at 85mph.
Agree with comments about the power tank. If you can charge at work it wouldn't be necessary.
The commuter screen should make a larger difference at higher speeds - maybe a 5-7% reduction, and corresponding improvement in top speed.