You can simply save all that content to an EHD or two and be done with it. You are not the average viewer..... I believe that the current Hopper HD size is optimial....
That requires buying an external hard drive. Also requires them to keep working. I had two EHDDs connected, but one recently crashed with a ton of movies on it. Now it isn't worth it to me to buy another because I'm sure it will just crash again at some point. Not to mention, that I honestly don't think about looking for content there (since you have to manually select the external drive). I don't think that many of us are the "average viewer". That said, I know several people who fill up their DVR. Most people who started with TIVOs back in the early DVR days had this method because the TIVO automatically filled up the extra space with their suggestions.
What is optimal about it? Seems like a strange word. Sufficient seems more appropriate with what you are saying. If it had a 2TB HDD would that be suboptimal for you? If so why?