Randy,
I was in Bfold last summer and there was a customer who was picking up their new Brompton from the shop. Apparently the customer had either borrowed or rented a Brompton from Bfold for one of the NYC area organized rides the week before. Perhaps you can call them to see if they actually do rent. If so, you can always give it a one week test on the bus and see how it works.
Ratdog