To add to what Kim says above, I’m 6’4”and bought my Brommie in 2010. Visited the London Bike Show that year (at Earls Court). On the Brompton stand, queue to speak to a technician. He took one look at me and said “Straight bars, telescopic seatpost. Next!”
He was right. I went to my LBS (which stocked Brommies then). Served by a chap whom I used to teach. Rode different models and different seatposts all morning. The technician had been right. S-bar & telescopic seatpost was the best fit.
I’ve also carefully measured/ photographed the Brommie next to my Bianchi road bike.My riding position is very similar on both bikes!
Distances? I have managed 90 miles in a day … but just for the challenge. Fifty miles is more than enough.
Have to say I love the bike.