Change Client Resolution of Viewed stream

My friends and I (with multiple monitors and slower PC's or low-speed/data-capped internet) have been wishing for a while to have the ability to change the resolution and/or framerate of the stream they are viewing (meaning the streamer will stream at their preferred resolution, and the viewer will be able to receive that stream in any resolution or framerate up to what the streamer's resolution is) as my friends and I would like to view a stream on another screen while playing a game but do not have the processing power to play the stream at high resolutions while running a game nor have the data-limit to afford high-resolution streams.