Energetic Border Collie that needs space and an active owner

this border collie named Milo has been living with us for a little over two years and he is probably the smartest dog i have ever owned. border collies are known for their energy and intelligence and that description fits him perfectly. when we first adopted him we lived in a house with a yard where he could run freely and spend hours playing with a ball. he quickly learned commands and even started responding to gestures instead of words. the problem started when we moved to a smaller place closer to the city. even though we take him on long walks every day it is obvious that he misses having space to run. he behaves very well indoors and never destroys things but you can see that he needs more activity than we can currently provide. for that reason we believe it would be better for him to live with someone who has an active lifestyle or more outdoor space.