One thing with electric bikes in particular is the faster you ride, the slower you charge (in terms of miles charged per hour).
At 45 mph you use charge at approximately 100 Wh/mile, or 4.5 kW average draw. You charge at 3 kW, or about 30 miles charged per hour. Therefore you will spend about 1.5 hours charging per hour riding. Total time with replenishment is 2.5 hours to go 45 miles, or 18 mph average.
At 55 mph you use charge at approximately 120 Wh/mile, or 6.6 kW average draw. You still charge at 3 kW, or about 25 miles charged per hour. Therefore you will spend about 2.2 hours charging per hour riding. Total time with replenishment is 3.2 hours to go 55 miles, or 17 mph average.
At 70-75 mph you use charge at approximately 180 Wh/mile, or 12.6 kW average draw. You still charge at 3 kW, or about 17 miles charged per hour. Therefore you will spend about 4-4.5 hours charging per hour riding (and note with the Empulse 10.0 you will probably only get about 60 miles at these speeds on a full charge). Total time with replenishment is 5.5 hours to go 70 miles, or 13 mph average.
Note that the Empulse 6 vs Empulse 10 doesn't affect the replenishment figures, you can just go for longer between charging stations and you have a larger buffer to start.