why that fast? wind drag is going to start being an issue you are going to be adding more power then you like probably,that being said if you are going hell for leather each ride you can probably find a dd motor that will fill the bill,I have had nice 1200 watt dd motors that seemed amply strong,28 mph was the about the top end though at top speed the battery is going away fast,get a nice 10-14 ah battery carry a spare one of equal power density and ride the thing till exhaustion install spare battery and scoot back home,that is going to get you honest range( to a certain extent)YMMV or just lose about 10 mph and extend range .
Wind drag is most certainly a factor, but I did my homework with the Grin trip simulator. Turned out irl after tweaking the route that 25 mph average is enough. Lugging a spare battery was never an option, nor was charging at work. My 28+28 km commute at 25 mph has never yet consumed more than 50% of my 48 V / 24,5 Ah battery, which is just the sort of duty cycle I wanted. It's a big battery but no regrets there.
