We have a Roku on the island with 1.6 mbps DSL and one at home with much higher speed internet.
We have a $7.99/month Netflix account that allows for 2 simultaneous viewings (different devices and content). One of us can watch via the Roku/TV connection and the other on a tablet with the Netflix app.
Roku does have a Sling channel so you can team the two together:
http://www.slingbox.com/roku