Redundancy, redundancy, redundancy.
I back up my irreplacable pics/videos on flash drives as well as DVDs (Verbatims). The files on DVD have generous Par files as well to fix possible data corruption. Hard drives will die, flash drives aren't as permanent as you would hope, DVDs can deteriorate. Maintain 3 redundant copies.
I would have no problem with online/offsite storage, as things like fires, floods, earthquakes, and hurricanes can destroy data as effectively as a simple hardware or media failure.
I am a retired Ford tech. Next to Fords, any computer is a piece of cake. (The cake, its not a lie)