Is it poss to still do another video?. The seq is still in lr but with keyframes from the 1st rendered video.

You can always export again via the LRTExport plugin. The only thing that get's deleted is the intermediary sequence, never the original files. Preserving the intermediary sequences makes sense, because it's quicker then to render again with different render settings. But as soon as you change something in the development, you would of course have to export a new intermediary sequence anyway.