I have had to rehome a working cocker about 5 years ago, as I just could not handle her, she wanted to work all day every day, and I did not have the time to do it. So she went to a farm, to work!
I guess I have grown up a bit now, and never take on something that I cannot keep until the rest of his/her days.
I have 3 lurchers, and will never rehome them.