If you really want to make it as long as you say, you're probably better off by rendering a still frame of the still part of the title, because otherwise Resolve will have to render the whole hour instead of just overlaying a still. And then just use the first 2 seconds of your animation at the beginning and the final 2 seconds at the end.
Or you could use the keyframe stretcher tool, which is easy once you know how, but it does require a little basic Fusion knowledge. Are you up for that?
Also: check out this thread which is related to your question:
viewtopic.php?f=22&t=126422