Using CHAdeMO, Zero charges the 2013+ batteries at approximately 1C. For the S and DS bikes, this can be limited by the maximum CHAdeMO DC charger output (some small CHAdeMO chargers limited to 50A, others 100A, a few are 125A).
Zero may also restrict the charge rate at high SOC, high cell temperature, etc. It will be difficult to get access to these sensor inputs.
Most J1772 EVSE will supply somewhere between 30A 208V AC (6.2 kW) and 32A 240V (7.7 kW). Assuming 90% charger efficiency, this gives you 5.6 to 6.9 kW per EVSE. Call it 6 kW DC.
You could tap multiple J1772 EVSE to increase your charging power, assuming there is more than one EVSE available. Terry Hershner does this to good effect.
Note that even though riding more quickly is less efficient, it will reduce your overall trip time as your charging power increases.
For example, with a stock ZF14.2 bike, times to ride + return to the same SOC
Riding 50 miles @ 55 mph takes 0.91 hours. Charging options:
1.3 kW (120V AC) 4.62 hours, 5.53 hours total
6 kW (J1772 x1) 0.98 hours, 1.89 hours total
12 kW (J1772 x2) 0.49 hours, 1.40 hours total (35.7 mph total)
Riding 50 miles @ 70 mph takes 0.71 hours. Charging options:
1.3 kW (120V AC) 5.56 hours, 6.47 hours total
6 kW (J1772 x1) 1.18 hours, 1.89 hours total
12 kW (J1772 x2) 0.59 hours, 1.30 hours total (38.4 mph total)
I would expect probably a ~20% improvement in range with typical bike fairings, or 60-80% improvement in range with a full slipstreamed fairing like Terry's.
Assuming a 70% improvement in range to 150 miles @ 70 mph = 59% reduction in power. You'd probably charge every 75-100 miles instead, but let's say 50 miles just for comparison purposes. Charging options:
1.3 kW (120V AC) 3.27 hours, 3.98 hours total
6 kW (J1772 x1) 0.58 hours, 1.29 hours total
12 kW (J1772 x2) 0.29 hours, 1.00 hours total (50 mph total)
With a sufficiently streamlined bike, a 500 mile trip would take approximately 7 hours to ride, with 4 stops to charge for about 40 minutes each. Total time around 10 hours.