I have an easy 10-mile round trip to work, mostly flats, one medium hill. Cruising speed averages 30-37 mph mph, with short speed bursts up to 43 mph. Power and reliability with a Tanaka 47R engine with Tanaka three-piece expansion pipe and shift kit.
I might be reassigned elsewhere, which would be a 35-mile round trip. Mostly flats with gridlock traffic.
JMO, a Honda 150 scooter would be a viable option for a 70-mile commute.