From my experience the only way to keep an external team engaged is to visit and to work with them. The longer, the better. During that time find out who are th

From my experience the only way to keep an external team engaged is to visit and to work with them. The longer, the better. During that time find out who are the best people to work with and make sure these folks stay on the project when you are away. Make a visit every 4-6 weeks and stay for at least 1 week.