On my extended route in next to highest setting on Haibike I get 28 miles... Its a mixed route but with plenty of hard climbs. ( upto Lockerbrook farm above Lady Bower). Mainly wide mtb paths with about 3 miles on road ( Snake pass)
I would easily beat this range on road work or easier mtb route. I can reduce range to circa 20 miles in high setting and really pushing. ( With dongle fitted I can drop that to 16 miles but do that route in 53 mins..)
You have to work really hard to flatten battery in under 25 miles..
I could get range upto 40 miles, taking things steady...
It is really difficult to give a figure, lets face it you coould stick bike in super eco, do 80% if work yourself and say you had a 80 mile range...
But , for me , in general mtb usage at steady pace ( averaging 12mph or so) I work on a range of 30 miles, no dongle, holding cadence between 70 and 80..
That's on Haibike sduro with 400 WH battery. I,m 105 kg, average fitness but do have heart probs.( Afib)
OT.. Bike priceless for getting active post Afib etc.