One way would be to copy(cntl+c) your last keyframe, move 5 seconds forward and paste it(cntl+v), then you can move them off as the wind blows.
Johnny Cuevas, Editor
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.