Yes, I have just been rendering the portion that I need.
Anyway, what I was hoping was that there would be something like the "split" capability that exists in most video editors that makes it easy to delete stuff I no longer need for the current clip. Guess that doesn't exist.
You can just delete the keys that you do not want/need and then drag the ones you want to start on frame 0/1 and save the project as a different name so you wont really lose any thing in case you decide you want the 1st part back again.